Founder Vesting Agreements: Cliff, Acceleration & Leaver Clauses Explained
Authored by - Souvik Das, Executive at Outsource360
On 24 October 2025 Lasso Inc., a Delaware start-up with four co-founders, terminated one of them for cause and, in the same notice, exercised its option to buy back his shares. He held a quarter of the company. All 1.5 million of his shares were still unvested, and the company paid USD 150 for them under his founder vesting agreement.
He'd signed it on 30 April 2025: a restricted stock purchase agreement under which he bought 1.5 million shares at USD 0.0001 each. A quarter would vest 12 months from 13 February 2025, the rest in monthly 1/48ths. If his service ended for any reason, Lasso had 120 days to buy back the unvested shares at the lower of USD 0.0001 a share and fair market value.
One clause mattered more than the rest. A qualifying termination without cause before the first vesting anniversary would have vested 25%, or 375,000 shares. A termination for cause vested nothing, and "Cause" for poor performance required notice and a chance to cure.
His complaint told the rest. From August 2025, he alleged, the other three co-founders froze him out of company information, bank accounts and systems. On 23 September the board sent a cure notice citing "persistent unsatisfactory performance" and listing deliverables to finish within 30 days, and on 23 October a notice that he hadn't met them. The termination came the next day, 112 days before his one-year cliff.
With his shares bought back, each of the other three founders' stakes rose from 25% to 33.33%. He sued on 31 October 2025, and on 30 September 2026 the Delaware Court of Chancery dismissed his complaint in its entirety (C.A. No. 2025-1264).
His claims, the court said, "arise principally from the terms of the restricted stock purchase agreement", and the implied covenant of good faith can't "supply contractual protections for which he did not bargain". Access and resources were foreseeable needs: "he could have bargained for them. He did not." When this guide was last verified, an appeal could still be filed until the end of October 2026.
Four clauses decide whether a founder like him leaves with nothing, a quarter or everything: the vesting start date, the cliff, the acceleration trigger and the definition of cause. Every founder vesting agreement has its own version of each, whether it's a US stock purchase agreement, a set of UK articles or an Indian shareholders' agreement.
Founder vesting means a founder owns shares from day one but earns them over time, commonly four years with a one-year cliff. If the founder leaves early, the unvested part goes back at cost or a nominal price or, in the UK, may convert into deferred shares. A founder vesting agreement sets the schedule, any acceleration and each leaver's price.
Below: where founder vesting sits in US, UK and Indian documents, how schedules and cliffs work, India's workarounds, resets at a funding round, single and double triggers, leaver categories and prices, who buys, and the tax in all three countries.
On this page
What is a founder vesting agreement in the US, UK and India?
How does a founder vesting schedule work?
What is a vesting cliff, and what if a founder leaves before it?
How does founder vesting work in India without restricted stock?
What happens to founder vesting at a funding round?
Single-trigger vs double-trigger acceleration: what should founders negotiate?
Good, bad and intermediate leavers: how are founder leaver clauses priced?
Who buys a leaver's shares, and are leaver clauses enforceable?
How is founder vesting taxed in the US, UK and India?
Frequently asked questions about founder vesting
What is a founder vesting agreement in the US, UK and India?
A founder vesting agreement is the set of terms that lets a company, or its other shareholders, take back a founder's unvested shares cheaply if the founder leaves early. It isn't one standard document: each country puts founder vesting in a different place, under different law, with a different tax treatment attached.
Which document holds founder vesting in each country?
This is where founder vesting lives in each country, as at 13 October 2026:
Country | Usual document | What the founder holds | What happens on leaving early | Tax election at the start |
United States | A restricted stock purchase agreement, or founder stock purchase agreement | Every share from day one, subject to the company's repurchase option | The company can buy back the unvested shares, often at cost or the lower of cost and fair market value | Section 83(b) election within 30 days of the purchase |
United Kingdom | Leaver provisions in the articles, alongside the investment or shareholders' agreement | Issued shares, subject to the leaver provisions | The unvested shares convert into deferred shares or must be transferred, as the articles say | Joint section 431 election within 14 days of acquisition |
India | A call option in the shareholders' agreement, repeated in the articles | Every share from allotment | Co-founders, a nominee or a trust can buy the unvested shares; the company only in narrow cases | None; a transfer below fair market value is taxed on both sides |
Sources: Treasury Regulation 1.83-2; Delaware General Corporation Law, section 202; Companies Act 2006, section 33; Income Tax (Earnings and Pensions) Act 2003, section 431; Companies Act, 2013, sections 44, 67 and 68; Income-tax Act, 2025, sections 79 and 92.
A US founder buys every share on day one, often for a fraction of a cent, and owns and votes them from the start. "Vesting" means the company's option to buy back unvested shares lapses in stages; the shares aren't issued as they vest. Agreements set the buyback price at cost, or the lower of cost and fair market value, for a tax reason: under Treasury Regulation 1.83-3(c)(1), shares aren't at risk of forfeiture to the extent the company must pay fair market value to take them back.
In the UK the leaver terms usually sit in the company's articles, which bind every shareholder, with the investment agreement alongside. Worth knowing: the statutory model articles contain no leaver or vesting provisions, so they have to be written in. In India the founder holds the shares outright from allotment, and vesting is rebuilt as a call option for the other shareholders, because Indian company law has no restricted stock.
What happens to a co-founder's shares without a vesting agreement?
What if nobody signed anything? The short answer: a departing co-founder keeps every share. Shares issued outright belong to their holder in all three countries. Takeover squeeze-outs aside, only a contract, the articles or a court order can force a sale, so vesting has to be agreed before anyone leaves.
But adding terms later is hard. A Delaware restriction binds shares already issued only if their holder signs or votes for it. In [2024] EWHC 3166 (Ch) an English court found unfair prejudice where a company added a "Bad Leaver" definition to its articles after a founder left, then converted his remaining shares.
And founding teams do split. Carta's June 2026 data shows 25% to 35% of two-founder teams formed between 2016 and 2021 had parted ways after five years. Vesting is only one of the terms worth settling on day one; the other clauses co-founders should agree alongside vesting, from IP assignment to deadlock, belong in the same documents.
How does a founder vesting schedule work?
A founder vesting schedule sets how fast a founder's shares stop being at risk of buyback. The common pattern is four years: nothing for 12 months, 25% at the one-year cliff, then 1/48th of the total monthly. Y Combinator calls this "a typical setup" in Silicon Valley; HSBC says its 2025 UK term-sheet data found a four-year period with a cliff most popular.
Monthly, quarterly or back-weighted: which schedule fits founders?
Monthly steps after the cliff are what Y Combinator describes and what Lasso's agreement used. The nearest data covers managers, not founders: in Carta's May 2025 analysis, about 88% of management grants at VC-backed and bootstrapped companies vested monthly, and 6% each quarterly or yearly.
Other steps appear in real documents. Session Corp's founders got shares vesting 25% a year in 2018, and an investors' rights agreement Motive Technologies filed with the SEC in 2025 vests staff stock 25% after 12 months, then quarterly over twelve quarters.
Back-weighted schedules load vesting towards the end: Snap's 2017 IPO filing showed employee restricted stock units vesting 10%, 20%, 30% and 40% across four years. Fair warning: applied to founder vesting, that leaves less vested if a founder leaves or is pushed out early.
Part-time founders can vest more slowly: a 2006 founder agreement filed with the SEC vested 1/48 a month while the founder worked at least three days a week, and 1/96 a month while working part time. In India, options carry a statutory minimum of one year between grant and vesting under rule 12(6)(a) of the Companies (Share Capital and Debentures) Rules, 2014; founder shares held subject to a call option have none.
Can founders get vesting credit for time already worked?
Yes, by choosing an earlier vesting start date. Lasso's agreement was signed on 30 April 2025 but counted from 13 February 2025, so its cliff fell 76 days sooner than it would have from the signing date. Who needs that? Founders who worked for months before signing.
Credit can also come as shares vested on day one. A 2016 founder agreement disclosed in an SEC filing by NYIAX vested 45,927 of 1,500,759 shares at once, and HSBC's article on its 2025 UK founder vesting data reports that 28% of term sheets gave 0% on day one, while only 13% gave 50% or more. But neither form of credit moves the US tax clock: the 30 days for an 83(b) election run from the date the shares are bought.
What is a vesting cliff, and what if a founder leaves before it?
A vesting cliff is the opening stretch of founder vesting, commonly 12 months, in which nothing vests; then a first block, 25% on a four-year schedule, vests at once. Without acceleration, a founder who leaves before the cliff has nothing vested, so every share falls under the leaver terms.
On a four-year schedule with a one-year cliff, this is what a founder holds at each point, as a share of the whole holding:
Point reached | Vested | Unvested | What happens to the unvested shares |
Founder leaves in month 11 | 0% | 100% | All go back under the leaver terms |
Founder leaves at month 12, the cliff | 25% | 75% | The unvested 75% go back |
Founder leaves at month 30 | 62.5% | 37.5% | The unvested 37.5% go back |
Company sold at month 30, single trigger with full acceleration | 100% | 0% | All vest when the sale closes |
Company sold at month 30, double trigger, founder kept on | 62.5% | 37.5% | Keep vesting monthly after the sale |
Then dismissed without cause, or resigns for good reason, within the agreed window | 100% | 0% | All vest on that exit |
Month 48, still in service | 100% | 0% | Nothing is left to buy back |
Illustration, not data: the percentages follow this one schedule, and any acceleration is whatever the founder's agreement says.
Is a 12-month founder vesting cliff standard?
It's the convention, not a rule. No law sets a founder cliff and no public dataset reports founder vesting cliff lengths; the closest data, Carta's May 2025 analysis of employee and management grants, found at least 95% of cliffs fell at one year.
Y Combinator's essay puts the rationale in one line: "if you leave or get fired within a year you walk away with nothing". A year lets co-founders learn whether they can work together, yet one who stays that long leaves with something.
So what protects a founder fired in month 11? Drafting: a clause vesting part of the shares on a termination without cause (like the opening example's 25%) and a cause definition with notice and a chance to cure. Courts rarely add either later.
When do a shorter cliff or milestone vesting make sense?
Milestones can replace time when a co-founder joins for a specific job. A London prosthetics start-up's 2018 founders' agreement, described in [2023] EWHC 1800 (Ch), gave an incoming co-founder 5% at once, 15% more on filing a provisional patent and parity once a funding round was prepared, the last two with deadlines.
But when investors arrived in 2019, new articles replaced that with three-year time vesting and good, voluntary and bad leaver classes, and those articles decided what happened when he left. The lesson: milestones need definitions as tight as any cause clause.
Some employers are shortening employee cliffs: OpenAI cut its 12-month cliff to six months in April 2025 and in December 2025 said it would drop it for new hires, Fortune reported. In our view founder cliffs manage team risk, so that's no evidence founder cliffs are shrinking.
How does founder vesting work in India without restricted stock?
Founder vesting in India has to be built from substitutes, because Indian company law has no restricted stock. A share is the holder's movable property from allotment, and section 67 of the Companies Act, 2013 lets a company buy its own shares only through a section 68 buy-back or a Tribunal-confirmed reduction, so the US model of a company buying back at cost has no direct equivalent. Is it possible at all in a private limited company? Yes, by the five routes below.
Reverse vesting, tranches or partly paid shares: which route works in India?
Here are the five routes to founder vesting in India, what limits each and where tax or FEMA bites, as at 13 October 2026:
Route | How it works | Main legal limit | Tax or FEMA watch-point |
Call option (reverse vesting) | Shares issued upfront; others can buy the unvested part if the founder leaves | On the text of section 68(5), the company cannot buy one founder's ordinary shares | A below-value price is taxed on both sides; FEMA pricing applies if a non-resident is involved |
Tranche allotments | Further shares are issued only as each period is served | A special resolution and a registered valuer's price for every tranche; no discount | The founder pays the rising value; shares for a non-resident need a fair-value price |
Partly paid shares | Shares issued partly paid, the balance called in stages | Table F lets the board forfeit only for an unpaid call | Non-residents pay 25% upfront, the rest within 12 months absent a monitoring agency |
Sweat equity | Shares issued for know-how or IP at a registered valuer's price | Yearly and overall caps, a three-year lock-in, no built-in clawback | Taxed as a perquisite on allotment |
Founder ESOPs | Options that vest over time and lapse unvested on leaving | Only inside rule 12's ten-year start-up window, with one year from grant to vesting | Taxed as a perquisite on exercise |
Sources: Companies Act, 2013, sections 53, 54, 62 and 68, and Schedule I, Table F; Companies (Share Capital and Debentures) Rules, 2014, rules 8, 12 and 13; Income-tax Act, 2025, section 17; RBI Master Direction - Foreign Investment in India, paragraphs 4.3 and 8.
The main founder vesting route is reverse vesting: every share is issued upfront, and the shareholders' agreement and articles give others a call option over the unvested part. Section 68(5) lists no buy-back of one founder's ordinary shares, so on its text the buyer is a co-founder, a nominee or an employee trust, not the company.
Securities law adds a wrinkle: SEBI's notification of 3 October 2013 allows options in shareholders' agreements and articles only where the seller has held the shares for a year from the contract, the price is lawful and delivery is actual. Whether it reaches private companies is unsettled, so careful drafting follows it anyway. An escrow agent or nominee holding the unvested shares makes the option easier to enforce, but the registered holder and the founder must each declare the beneficial interest under section 89, and an undeclared interest can't be enforced.
Can founders use sweat equity or founder ESOPs instead?
Sweat equity rewards know-how or IP with shares at a registered valuer's price, within yearly and overall caps, and locks them in for three years with no clawback, so it rewards past work rather than vesting future work. Founder ESOPs give true time-vesting. Rule 12 bars promoters and directors holding more than 10% from options, but lifts the bar for a start-up for ten years from incorporation, which decides when a DPIIT-recognised startup can grant options to its founders.
One catch: rules 8 and 12 still define a start-up by DPIIT's 2019 notification, G.S.R. 127(E), which G.S.R. 108(E) superseded on 4 February 2026, and neither reads the old reference as the new one. The safe course is to rely on the start-up limits only where a company meets both definitions. Even then, options differ from founder vesting on shares in three ways: they carry no votes until exercised, unvested options lapse on resignation or termination under rule 12(8)(f), and tax falls at exercise as a perquisite under section 17(1)(d) of the Income-tax Act, 2025.
India may get closer to restricted stock. Clause 28 of the Corporate Laws (Amendment) Bill, 2026 would add schemes "linked to the value of the share capital", meant for restricted stock units, to section 62(1)(b). The Joint Committee's 3 August 2026 report accepted it, but the Bill is still pending.
What happens to founder vesting at a funding round?
At a priced round, investors may ask founders to put some already-vested shares back under a schedule, known as a founder vesting reset or re-vest. It's negotiated, not automatic: NVCA's 2020 model term sheet offers it only as an optional bracketed clause, and its footnote says investors "may also conclude not to change founder vesting".
Why do investors ask founders to re-vest, and how often?
Why ask? Team risk: a fully vested founder could quit soon after the round. Recent figures on how often investors ask come from the UK: of 711 term sheets from 2025 deals in HSBC Innovation Banking's 2026 guide, 58% included founder vesting (65% at seed) and 42% were silent.
The only US figure is old: a study of 200 US venture investments made between 1987 and 1999 found founder vesting in almost 42% of rounds and almost 55% of pre-revenue ones. No public dataset counts how often investors re-vest shares founders had already earned.
Real cases show the shape. Lithos Industries closed a preferred round in February 2023 "conditioned on" a co-CEO signing a repurchase agreement that deemed 3,250,000 of his 5,000,000 shares unvested, vesting over 24 monthly instalments, while 1,750,000 "Guaranteed Shares" could never be bought back, the Delaware Court of Chancery recorded. So it pays to know what investors check about founder vesting in diligence before a term sheet arrives.
How can founders negotiate a vesting reset?
Here are the points founders can negotiate in a reset, each taken from a real agreement:
Credit for time served: keep part of the holding outside the reset, as the Lithos co-CEO kept 1,750,000 shares.
A smaller re-vested share: the 2006 founder agreement filed with the SEC re-vested half of the founder's shares, not all.
No new cliff: Lithos's re-vested shares vested monthly from the first month after closing.
Acceleration as the trade: full vesting on a resignation for good reason, as Lithos's agreement gave.
A narrow cause definition with written notice and a cure period; Lithos's agreement allowed 30 days.
Proper approval: a board resolution, and the signature of every founder whose shares are re-cut.
Process matters as much as terms. Session Corp re-vested its founders' shares in 2022 after a SAFE round, then bought out two founders for USD 19.50 each; the Delaware courts undid the buyout because the board never approved it, a step that "went beyond what a CEO could do unilaterally" (affirmed in June 2026).
In the US, Revenue Ruling 2007-49 treats re-imposing vesting on already-vested shares as no new transfer, so no new 83(b) election is needed, and it sets no minimum holding period. Swapping into a new holding company differs: the new restricted shares fall under section 83 again. The ruling doesn't cover shares that were still partly unvested when the round re-cut them, and advisers often file a protective election there.
In the UK, restrictions placed on shares acquired without them fall outside the restricted-securities rules, HMRC's manual says, but re-cutting an existing restriction is a chargeable event that a joint section 430 election, made within 14 days, can address. In India a reset is an amendment to the shareholders' agreement and articles: no shares are issued, so on the text of the tax and FEMA rules nothing is taxed or reported.
Single-trigger vs double-trigger acceleration: what should founders negotiate?
Acceleration makes founder vesting run ahead of schedule. Single-trigger acceleration vests unvested shares on one event, such as a change of control; double-trigger needs a change of control and then the founder's dismissal without cause or resignation for good reason within an agreed window. Neither happens by default: without a clause, unvested shares keep their schedule or are dealt with in the deal.
How do single, double and partial acceleration differ?
The three forms compare like this, each with an example from an agreement filed with the SEC:
Feature | Single trigger | Double trigger | Partial |
What sets it off | One event, such as a change of control | A change of control, then dismissal without cause or resignation for good reason within a set period | Either trigger, or a termination with no sale |
What vests | All, or an agreed share, of the unvested shares | All, or an agreed share, on the second trigger | A fixed slice, such as 25% or the next months' vesting |
Filed example | 2007 founder-CEO agreement: all unvested founder stock on a change in control | 2006 founder agreement: all unvested shares on an involuntary termination or termination without cause within 18 months after a change of control, against a release | 2007 founder-CEO agreement: the next 18 months' vesting on an involuntary termination |
US golden-parachute rules | Tested under section 280G | Tested under section 280G once the second trigger fires | Tested under section 280G if tied to a sale |
Main drafting risk | Founders have less reason to stay after the sale | How cause and good reason are defined | Which event counts, and how much vests |
Sources: founder-CEO agreement of 2007, filed with the SEC in 2014; founder agreement of 2006, filed with the SEC in 2011; Internal Revenue Code, section 280G.
How common each form is isn't publicly measured: no public dataset counts acceleration in founder vesting agreements, and NVCA's 2020 model term sheet has no acceleration term at all. Claims that double trigger is "the market standard" rest on practice, not data.
Buyers and later investors favour double trigger for a practical reason: a buyer paying for a team wants founder vesting still running after closing, while single trigger hands the founders everything on day one. But double trigger isn't a tax shield: in the US, acceleration that follows a sale is still tested under section 280G's golden-parachute rules.
So what should founders negotiate? Mostly the definitions behind the second trigger.
Which definitions decide acceleration: change of control, cause and good reason?
A change of control needs numbers: NVCA's June 2026 model voting agreement uses more than 50% of the voting power, or a deal the charter treats as a liquidation. Cause carries the most money. The 2007 founder-CEO agreement limited it to misconduct causing material harm, a felony conviction, fraud, repeated substance abuse and uncured breaches of its IP or other agreements. Good reason lets a founder resign and still count as pushed out: Lithos's agreement covered a material cut in overall pay and benefits or a material diminution of responsibilities.
Timing can decide it. On 23 June 2023 Lithos emailed its co-CEO's termination at 10:08 a.m.; his "Good Reason" resignation, which would have accelerated his vesting, came at 11:29. The company bought back 2,708,333 unvested shares for USD 27.08 and won summary judgment in November 2024. Even punctuation counts: in 2021 Delaware's courts read a founder's acceleration clause missing a closing bracket as double-trigger, in line with a parallel clause for directors, and rejected his single-trigger claim (Delaware Supreme Court, No. 84, 2021).
In India no statute covers acceleration, so it's drafted as the call option lapsing; for founder ESOPs, rule 12(8)(f) of India's Share Capital Rules cancels unvested options the day employment ends, so a double trigger must vest them no later than that day. Buyers can also assume, cash out or replace unvested shares in the deal itself, which is how a buyer treats unvested equity at closing in an Indian sale.
Good, bad and intermediate leavers: how are founder leaver clauses priced?
Founder vesting fixes how many shares are unvested when a founder leaves; the leaver clause fixes their price. In the US and UK documents courts and the SEC have published, unvested shares go back at cost, nominal value or as deferred shares whatever the reason; the good, bad or intermediate label mainly decides the vested shares.
This table shows what published founder vesting documents do with a departing founder's shares, country by country (drafting practice, not law):
Country | How the shares come back | Unvested shares, any leaver | Vested shares, good leaver | Vested shares, bad leaver |
United States | The company exercises its repurchase option | At cost, or the lower of cost and fair market value | Kept | Kept, unless the agreement lets the company buy them too on a termination for cause |
United Kingdom | The articles convert them into deferred shares or force a transfer | Converted into deferred shares, or transferred at nominal value or another fixed price | Kept | Can be converted or transferred too, at a nominal or other fixed price |
India | A call option for co-founders, a nominee or a trust; the company only in narrow cases | Transferred at the price the SHA sets, within FEMA limits if a non-resident is involved | Kept, unless the SHA says otherwise; one 2025 SHA called for 20% | As the SHA sets; a below-value price is taxed on both sides |
Sources: Treasury Regulation 1.83-3; Delaware General Corporation Law, section 202; Companies Act 2006, section 33; [2023] EWHC 1800 (Ch); [2023] EWHC 2451 (Ch); [2023] EWHC 3017 (Ch); Delhi High Court, O.M.P.(I)(COMM.) 48/2026; Income-tax Act, 2025, sections 79 and 92.
Who counts as a good, bad or intermediate leaver?
No statute defines these categories; the founder's documents do. A bad leaver is typically a founder dismissed for cause, as the documents define it, or one who resigns where they say so ([2023] EWHC 2451 (Ch)): in articles English courts have quoted, fraud, gross misconduct or a serious breach of the service contract.
An intermediate leaver is a category some documents add for a founder who resigns before an agreed date. In one set of UK articles a resigning founder would keep half the shares that would have vested for a good leaver, the rest becoming deferred shares ([2023] EWHC 1800 (Ch)). A good leaver is everyone else, such as a founder dismissed without cause, and in those documents keeps the vested shares.
And a founder who simply resigns? That's the contested case. UK Private Capital (formerly the BVCA) dropped resignation from the Bad Leaver definition in its model documents in February 2025, saying it "is rarely a Bad Leaver event" and that investors who insist usually say so in the term sheet.
Even a good leaver can lose vested shares. A 2025 Indian shareholders' agreement quoted by the Delhi High Court in February 2026 required a promoter dismissed without cause to give up 20% of their vested shares and, at the lead investor's option, all unvested ones at the lower of face value and "the lowest permissible price per Equity Security under applicable Law". The definitions, not the labels, decide what a founder keeps, so read the cause, good-reason and resignation clauses before signing.
How is a leaver's price set, and when is it paid?
Settle the mechanics early if you can: only 49% of the 2025 UK term sheets in HSBC's guide included leaver provisions, leaving the rest to the long-form documents. In India, "fair value" needs a definition, because three regimes value the same share differently: a registered valuer for company law, an arm's-length method certified by a chartered accountant or merchant banker for FEMA, and the book-value formula in rule 57 of the Income-tax Rules, 2026 for tax. So a founder vesting agreement should name which valuation report can fix a leaver's fair market value.
A price set at "the lowest permissible price" under law, as in the Delhi case, hands the number to whatever floor the law sets, rather than to the parties. Timing is contractual too: the 2006 SEC-filed agreement gave the company 60 days to exercise its buyback and let it pay by cancelling a founder's promissory note, while Lasso's allowed 120 days.
Who buys a leaver's shares, and are leaver clauses enforceable?
Who may take back a leaver's shares depends on company law, and whether a founder vesting price holds depends on contract law. A US company repurchases under its option, subject to capital rules; a UK company can buy its own shares only within tight limits, one reason articles convert them instead; and an Indian company generally can't buy one founder's shares at all.
Company, co-founders or deferred shares: who buys in each country?
Under section 160 of Delaware's corporation law, a company may not buy back shares for cash or property while its capital is impaired or if the purchase would impair it, a test a repurchase at cost rarely strains but a cash-poor company must still check. In the UK, the Companies Act 2006 lets a company buy only fully paid shares, from distributable profits, a fresh issue or capital under the statutory procedure, plus a small yearly sum if its articles allow. Converting leaver shares into deferred shares avoids most of that. A UK transfer for more than GBP 1,000 carries 0.5% stamp duty, so a nominal leaver price of GBP 1,000 or less attracts none.
In India the buyer is generally a co-founder, a nominee or an employee trust, and a private company may fund a trust or nominee to buy, subject to its loan rules, because the section 67(2) bar on financial assistance applies only to public companies. Indian-resident founders of a US parent face a further limit on founder vesting buybacks. Under India's Overseas Investment Rules, 2022, a resident individual may make an overseas direct investment only in an operating foreign company that, where the individual controls it, has no subsidiary, though sweat equity and employee-scheme shares are exempt. Transfers of a founder's shares to a non-resident, buybacks included, must be at arm's length under rule 16, and rule 17(4)(ii) requires a year's holding before disinvestment, so on the rules' text a US-style buyback at cost before the cliff collides with Indian exchange control.
When can a court strike down a bad-leaver price?
In England the test comes from [2015] UKSC 67: a clause is a penalty only if, as a secondary obligation, it imposes a detriment "out of all proportion to any legitimate interest of the innocent party in the enforcement of the primary obligation". The court upheld a forced sale of a defaulting seller's shares at a price excluding goodwill. English judges have since treated leaver transfers as primary obligations outside the rule: at trial in [2018] EWHC 1040 (Ch), and in [2023] EWHC 3017 (Ch), where a Master, before trial, called a GBP 1 "Very Bad Leaver" price for shares a pharmacy-business founder put at about GBP 8 million a "price adjustment mechanism".
Does India follow? No Indian court had ruled on the point by 13 October 2026. Section 74 of the Indian Contract Act applies only "when a contract has been broken", and the Supreme Court, in (2015) 4 SCC 136, treats loss as essential. So a price triggered by resignation or dismissal without cause should fall outside it, while a nominal price triggered by breach risks being cut to reasonable compensation.
Delaware courts enforce the terms as written: Delaware's Supreme Court held in December 2024 that forfeiture-for-competition terms in equity awards are contract terms, not restraints of trade, and what undoes a repurchase is faulty process, as Session Corp's unapproved buyout showed.
How is founder vesting taxed in the US, UK and India?
Founder vesting is taxed at different moments in each country. The US and UK tax the growth in value as shares vest unless the founder elects, within days of acquiring them, to be taxed at the start. India taxes founder shares at issue only if they're issued below fair value, and taxes a below-value clawback on both sides.
83(b), section 431 and 280G: the US and UK tax rules
Without an election, US law taxes founder vesting tranche by tranche: each is pay when it vests, on its value then minus what the founder paid, and the capital-gains holding period starts only at vesting; acceleration counts as vesting.
An 83(b) election, made "not later than 30 days after the date of such transfer", taxes unvested shares at purchase instead, usually on a spread of nil. It's irrevocable without IRS consent and goes on Form 15620 or a written statement, by post or online through an IRS Online Account. Missed the 30 days? No relief rule extends them.
But if elected shares are later bought back at cost, the tax paid isn't refunded. The election also starts the holding period at purchase and (on the usual reading) the small-business stock exclusion clock with it: for stock acquired after 4 July 2025 that exclusion covers 50% to 100% of the gain after three to five years.
Acceleration on a sale can also trip the golden-parachute rules: once change-related payments reach three times a founder's base amount, everything above one times it loses the company's deduction and bears a 20% excise tax. An 83(b) doesn't help, though a private company can exempt the payments by a disclosed vote of more than 75% of the other shareholders' voting power.
In the UK, founders' shares count as employment-related securities, and leaver terms paying less than market value make them restricted, so income tax can arise as restrictions lift. A section 431 election, signed jointly by company and founder within 14 days of acquisition, values the shares as if unrestricted, taking later growth out of income tax, usually at little cost at incorporation. It also removes most of the risk in an open question: whether converting leaver shares into deferred shares is a forfeiture. On a later sale, Business Asset Disposal Relief taxes gains at 18% from 6 April 2026, up to GBP 1 million in a lifetime, but only for a seller who held 5% and was an officer or employee throughout the two years before, which a founder who left and sold later can fail.
India: tax on issuing, clawing back and accelerating founder shares
Founder shares issued at fair value, usually face value at incorporation, carry no tax. Issued below it to an employee or employee-director, the shortfall is a perquisite under section 17(1)(d) of the Income-tax Act, 2025; for other founders, whether section 92(2)(m) of the same Act reaches a fresh allotment is disputed.
A clawback below fair market value is taxed on both sides: section 79 of the Income-tax Act, 2025 treats the leaver as paid full value, and section 92(2)(m) taxes the buyer on the whole shortfall once it exceeds Rs 50,000, unless the buyer is a relative. Fair market value there means rule 57's book-value formula, which works from the balance sheet, so it can sit far below a round's headline valuation, and no rule exempts founders from either charge.
Re-vesting, acceleration and the lapse of a call option move no shares, so on the text of the Income-tax Act, 2025 they create no tax event. Tax waits for a sale; the holding period runs from allotment, and unlisted shares held over 24 months are long-term, taxed at 12.5% under section 197 of that Act. Sweat equity is taxed as a perquisite on allotment and founder ESOPs on exercise, and the deferral of that tax applies only to an eligible start-up holding an Inter-Ministerial Board certificate under section 140 of that Act.
Frequently asked questions about founder vesting
How is reverse vesting different from ordinary vesting?
Reverse vesting gives the founder every share upfront and lets others buy back the unvested part on an early exit. With ordinary vesting, as for employee options, there's nothing to own until each tranche vests. In India it's a call option in the shareholders' agreement and articles.
Do founders have to pay for their shares?
Yes, but it can be very little. US founders often buy at a nominal price; Lasso's co-founder paid USD 0.0001 a share, or USD 150 for 1.5 million shares. In India, founder shares issued at fair value, usually face value at incorporation, carry no tax.
Is four years with a one-year cliff standard for founders?
It's the convention, not a rule. Y Combinator calls it "a typical setup" in Silicon Valley and HSBC found a four-year period with a cliff most popular in 2025 UK data, but no public dataset reports founder cliff lengths; Carta's 95% figure covers employee and management grants.
Do investors require founder vesting before they invest?
Not necessarily. In HSBC Innovation Banking's 2026 guide, 58% of 711 UK term sheets from 2025 deals included founder vesting (65% at seed) and 42% were silent. A 1987-1999 US study found it in almost 42% of rounds, and no public dataset counts how often investors re-vest.
Does founder vesting work in an Indian private company?
Yes, through substitutes. Founder vesting there mainly means reverse vesting: shares issued upfront, with a call option for co-founders, a nominee or a trust, because on the text of section 68(5) the company can't buy them back. Tranches, sweat equity and founder ESOPs also work.
Can founder vesting be tied to milestones instead of time?
Yes. A London start-up's 2018 founders' agreement, described in [2023] EWHC 1800 (Ch), gave a co-founder 5% at once, 15% more on filing a provisional patent and parity once a funding round was prepared. New articles replaced it with time vesting when investors arrived in 2019.
Can investors make founders re-vest shares that have already vested?
Not automatically: it's negotiated. NVCA's 2020 model term sheet offers a re-vest only as an optional bracketed clause, though Lithos's 2023 round was "conditioned on" a co-CEO signing one. Founders can bargain for credit for time served and acceleration.
Can vesting or leaver terms be added after the shares are issued?
Only with care. A Delaware restriction binds issued shares only if their holder signs or votes for it, and an English court found unfair prejudice in [2024] EWHC 3166 (Ch) where a Bad Leaver definition was added after a founder left. Session Corp's buyout also failed without board approval.
What happens if a US founder misses the 83(b) deadline?
Each tranche is then taxed as pay when it vests, on its value then minus what the founder paid, with the holding period starting at vesting. The 30 days run from the purchase, not the vesting start date, and no relief rule extends them.
Do UK founders need a section 431 election for shares that vest?
No law requires one, but it's often advisable. Leaver terms paying less than market value make founders' shares restricted, so income tax can arise as restrictions lift. A joint election within 14 days of acquisition values them as if unrestricted, usually at little cost at incorporation.
Why do acquirers prefer double-trigger acceleration?
Because a buyer paying for a team wants vesting still running after closing, while single trigger hands founders everything at the sale. Double trigger vests only if the founder is then dismissed without cause or resigns for good reason. No public dataset shows how common it is.
What is an intermediate leaver?
A category some documents add for a founder who resigns before an agreed date. In one set of UK articles, quoted in [2023] EWHC 1800 (Ch), a resigning founder would keep half the shares that would have vested for a good leaver, the rest becoming deferred shares.
Can a founder lose vested shares as a bad leaver?
Yes, where the documents say so. UK articles in reported cases converted a bad leaver's whole holding, US for-cause terms can reach vested shares, and one 2025 Indian shareholders' agreement called for 20% of even a good leaver's vested shares. The definitions decide.
What happens to unvested founder shares when the company is sold?
They don't vest automatically, only if the agreement accelerates them: on the sale alone (single trigger) or on a later dismissal without cause or good-reason resignation (double trigger). Otherwise they keep their schedule or are dealt with in the deal.
Can an Indian company buy back a departing founder's unvested shares?
Generally no. Section 68(5) of the Companies Act, 2013 allows buy-backs only pro rata, on the open market or of sweat-equity and ESOP shares, so on its text one founder's ordinary shares can't be singled out. A co-founder, a nominee or an employee trust buys instead.
References
United States (US Code and Code of Federal Regulations; Internal Revenue Service; State of Delaware; Delaware courts; SEC filings; model documents).
26 U.S. Code section 83 (property transferred in connection with performance of services), US Congress, via Cornell Law School's Legal Information Institute.
26 U.S. Code section 280G (golden parachute payments), US Congress.
26 U.S. Code section 1202 (partial exclusion for gain from certain small business stock), US Congress.
26 CFR 1.83-2 (election to include in gross income in year of transfer), US Department of the Treasury.
26 CFR 1.83-3 (meaning and use of certain terms), US Department of the Treasury.
Form 15620, Section 83(b) Election (Rev. 4-2025), Internal Revenue Service.
Revenue Ruling 2007-49, Internal Revenue Bulletin 2007-31, Internal Revenue Service.
Delaware Code, Title 8, Chapter 1, Subchapter V (stock and dividends, including section 160), State of Delaware.
Delaware Code, Title 8, Chapter 1, Subchapter VI (stock transfers, including section 202), State of Delaware.
Supreme Court of the State of Delaware, No. 110, 2024, decided 18 December 2024 (LKQ Corporation).
Founder agreement of 2006, Exhibit 10.11 to a Form S-1/A filed on 7 January 2011, US Securities and Exchange Commission (EDGAR).
Founder-CEO agreement of 2007, Exhibit 10.4 to a Form S-1 filed on 4 February 2014, US Securities and Exchange Commission (EDGAR).
NYIAX, Inc., Exhibit 10.45 to Form S-1 (1 June 2022), US Securities and Exchange Commission (EDGAR).
Motive Technologies, Inc., Amended and Restated Investors' Rights Agreement of 20 May 2025, Exhibit 4.2 to Form S-1 (23 December 2025), US Securities and Exchange Commission (EDGAR).
Snap Inc., Form S-1/A (27 February 2017), US Securities and Exchange Commission (EDGAR).
NVCA Model Term Sheet (2020 edition; no longer listed among NVCA's model documents), National Venture Capital Association.
NVCA Model Voting Agreement (updated June 2026), National Venture Capital Association.
United Kingdom (legislation.gov.uk, The National Archives; HMRC and gov.uk; UK courts via Find Case Law; UK Private Capital).
Companies Act 2006, section 33 (effect of company's constitution), UK Parliament.
Companies Act 2006, section 692 (financing of purchase of own shares), with sections 690 and 691, UK Parliament.
The Companies (Model Articles) Regulations 2008 (SI 2008/3229), Schedule 1 (model articles for private companies limited by shares), UK Government.
Income Tax (Earnings and Pensions) Act 2003, section 423 ("restricted securities" and "restricted interest in securities"), UK Parliament.
Income Tax (Earnings and Pensions) Act 2003, section 430 (election for outstanding restrictions to be ignored), UK Parliament.
Income Tax (Earnings and Pensions) Act 2003, section 431 (election for full or partial disapplication of this Chapter), UK Parliament.
Employment Related Securities Manual, ERSM30300 (restricted securities: securities acquired on or after 16 April 2003: introduction), HM Revenue and Customs.
Business Asset Disposal Relief, HM Revenue and Customs (gov.uk).
Tax when you buy shares, HM Revenue and Customs (gov.uk).
Model Documents for Early Stage Investments: key changes to February 2025 edition, UK Private Capital (formerly the BVCA).
[2015] UKSC 67, Supreme Court of the United Kingdom, 4 November 2015.
[2018] EWHC 1040 (Ch), High Court of England and Wales, Chancery Division, 8 May 2018.
[2023] EWHC 1800 (Ch), High Court of England and Wales, Chancery Division, 19 July 2023.
[2023] EWHC 2451 (Ch), High Court of England and Wales, Chancery Division, 6 October 2023.
[2023] EWHC 3017 (Ch), High Court of England and Wales, Chancery Division (a Master's interlocutory decision, 30 November 2023).
[2024] EWHC 3166 (Ch), High Court of England and Wales, Chancery Division, 19 December 2024.
India (India Code; e-Gazette; Parliament; Central Board of Direct Taxes; Reserve Bank of India; SEBI; courts).
Companies Act, 2013, section 44 (nature of shares or debentures), Ministry of Corporate Affairs, via India Code.
Companies Act, 2013, section 53 (prohibition on issue of shares at discount), via India Code.
Companies Act, 2013, section 54 (issue of sweat equity shares), via India Code.
Companies Act, 2013, section 62 (further issue of share capital), via India Code.
Companies Act, 2013, section 67 (restrictions on purchase by company or giving of loans by it for purchase of its shares), via India Code.
Companies Act, 2013, section 68 (power of company to purchase its own securities), via India Code.
Companies Act, 2013, section 89 (declaration in respect of beneficial interest in any share), via India Code.
Companies Act, 2013, Schedule I, Table F (articles of association of a company limited by shares), via India Code.
Companies (Share Capital and Debentures) Rules, 2014, rules 8, 12 and 13 (text as notified in 2014; later amendments include G.S.R. 574(E) of 16 August 2019 for rule 12 and G.S.R. 372(E) of 5 June 2020 for rule 8), Ministry of Corporate Affairs, via India Code.
G.S.R. 108(E), 4 February 2026 (start-up definition), Department for Promotion of Industry and Internal Trade, Gazette of India.
Corporate Laws (Amendment) Bill, 2026 (Bill No. 85 of 2026), as introduced on 23 March 2026, Lok Sabha.
Income-tax Act, 2025, section 17, Central Board of Direct Taxes.
Income-tax Act, 2025, section 79, Central Board of Direct Taxes.
Income-tax Act, 2025, section 92, Central Board of Direct Taxes.
Income-tax Act, 2025, section 140, Central Board of Direct Taxes.
Income-tax Act, 2025, section 197, Central Board of Direct Taxes.
Income-tax Rules, 2026 (G.S.R. 198(E), 20 March 2026), rule 57, Central Board of Direct Taxes.
Master Direction - Foreign Investment in India (updated up to 15 June 2026), Reserve Bank of India.
Foreign Exchange Management (Overseas Investment) Rules, 2022 (G.S.R. 646(E), 22 August 2022), Ministry of Finance, via the Reserve Bank of India.
Notification No. LAD-NRO/GN/2013-14/26/6667 of 3 October 2013 under sections 16 and 28 of the Securities Contracts (Regulation) Act, 1956, Securities and Exchange Board of India.
Indian Contract Act, 1872, section 74 (compensation for breach of contract where penalty stipulated for), via India Code.
Supreme Court of India, judgment of 9 January 2015, (2015) 4 SCC 136.
Delhi High Court, O.M.P.(I)(COMM.) 48/2026, judgment of 10 February 2026.
Data and research.
Venture Capital Term Sheet Guide 2026, Volume 1 (711 term sheets, 2025 UK deals), HSBC Innovation Banking.
Founder vesting: what early-stage founders need to know, HSBC Innovation Banking.
Dynamic duos: two-founder teams are divvying up their equity more equally than ever (18 June 2026), Carta data.
What are the most common structures for portfolio company equity in PE? (16 May 2025), Carta data.
Financial Contracting Theory Meets the Real World: An Empirical Analysis of Venture Capital Contracts, NBER Working Paper No. 7660 (US investments, 1987-1999), National Bureau of Economic Research.
How to split equity among co-founders, Y Combinator.
Amid talent war, OpenAI ends new hire vesting restriction (15 December 2025), Fortune.
Disclaimer
This article is for education and general business information only and is not legal, financial or tax advice. It states the rules and cases as at 13 October 2026, and several may change, especially the Lasso ruling (an appeal could be filed until the end of October 2026), the Corporate Laws (Amendment) Bill, 2026, the DPIIT start-up definition, UK tax rates and US tax rules. Founder vesting terms need advice in each country whose company law or tax applies, and in India on FEMA too. Before signing or acting, consult a qualified professional: a lawyer, company secretary or chartered accountant, and a US or UK tax adviser where relevant.
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