Founder Vesting Schedule: Cliffs, Leavers, Acceleration

A founder vesting schedule defines how a founder earns their shares over time, so that someone who leaves early does not keep equity for work they will never do. The most common structure is four years with a one-year cliff: no shares vest in the first twelve months, a quarter vests at the one-year mark, and the remainder vests in equal monthly (or quarterly) instalments over the next three years. For founders, this is usually implemented as reverse vesting, where the company can buy back unvested shares if the founder leaves.

This guide covers how the schedule works month by month, how leaver terms change the outcome, when acceleration applies, and what to negotiate.

Why founders vest their own shares

It can feel odd to put conditions on shares you created yourself. The logic becomes clear when you think about the alternative. Two founders split the company 50/50 without vesting. After eight months, one leaves to take a job. The remaining founder spends the next five years building the company, raises money and hires a team, while the departed founder still owns half of it.

That situation is bad for the remaining founder, and it is a red flag for investors, because a large passive shareholder reduces the incentive of the people actually doing the work. Most professional investors will ask for founder vesting before investing, if it is not already in place. Putting it in at founding, on terms the founders choose, is usually better than having it imposed during a round.

Vesting also makes the co-founder equity split easier to agree on. If everyone knows that equity is earned over time, a slightly imperfect split is much less risky.

How a 4-year vesting schedule with a 1-year cliff works

Worked example

A founder holds 4,000,000 shares on a four-year schedule with a one-year cliff and monthly vesting after the cliff. Total vesting period: 48 months, so each month represents 4,000,000 / 48 ≈ 83,333 shares.

Time since vesting start	Vested shares	Vested %	Unvested shares
6 months	0	0%	4,000,000
11 months	0	0%	4,000,000
12 months (cliff)	1,000,000	25%	3,000,000
18 months	1,500,000	37.5%	2,500,000
24 months	2,000,000	50%	2,000,000
36 months	3,000,000	75%	1,000,000
48 months	4,000,000	100%	0

If the founder leaves at month 18, they keep 1,500,000 shares (18/48 of the total). The company can repurchase the remaining 2,500,000 unvested shares under the terms in the founder agreement. If they leave at month 11, they keep nothing, because the cliff has not been reached.

Why the cliff exists

The cliff is a trial period. It prevents someone who leaves after a few weeks or months from walking away with a small but permanent stake that clutters the cap table forever. After the cliff, vesting becomes gradual, so there is no single date with a huge jump that creates an incentive to leave just after it.

The vesting start date

The vesting start date does not have to be the incorporation date. If founders worked on the company for a year before incorporating, they can agree that part of that time counts. This is called vesting credit.

A common compromise: credit some of the prior work (for example, six months), but not all of it, especially if a funding round is coming and investors want the team committed for a meaningful period afterwards. Whatever you agree, write down the start date for each founder explicitly. Different founders can have different start dates if they joined at different times.

Reverse vesting vs standard vesting

For employees, vesting usually applies to stock options: the employee receives the right to buy shares, and that right vests over time.

For founders, the more common mechanism is reverse vesting:

1. Founders receive all their shares at incorporation and are the legal owners.
2. The founder agreement gives the company (or the other shareholders) a right to buy back unvested shares if the founder leaves.
3. The buyback price for unvested shares is typically the nominal value or the original issue price, which is very low.
4. As time passes, the buyback right lapses on a growing portion of the shares.

How this is implemented depends on the jurisdiction and company form. In some countries it is done through repurchase rights in a shareholder agreement; in others through call options held by co-founders or the company. Tax consequences can be significant: in the US, for example, founders with reverse-vesting shares commonly consider an 83(b) election within a short deadline after receiving the shares. Other countries have different rules. Ask a tax adviser in your country before shares are issued.

Good leaver and bad leaver terms

Many founder agreements, particularly in Europe, distinguish between reasons for leaving. The definitions are negotiable, but the general pattern looks like this:

Leaver type	Typical triggers	Typical consequence
Good leaver	Death, serious illness, termination without cause, sometimes leaving after a defined minimum period	Keeps vested shares; unvested shares bought back at nominal value
Bad leaver	Termination for serious cause, breach of non-compete or material obligations, sometimes leaving voluntarily before a defined date	May lose some or all vested shares too, or must sell them at a low price
Intermediate	Voluntary resignation in some agreements	Keeps vested shares, possibly at reduced value

Bad leaver terms protect the company against serious misconduct, but overly broad definitions can be unfair. For example, a clause that treats any voluntary departure as "bad", at any time, can leave a founder who worked for three years with almost nothing. Negotiate definitions carefully and have your own lawyer review them.

Acceleration on an acquisition

Acceleration means unvested shares vest early when a certain event occurs, usually an acquisition.

• Single-trigger acceleration: some or all unvested shares vest when the company is acquired. Simple for founders, but acquirers often dislike it because the team may have little incentive to stay after the deal.
• Double-trigger acceleration: unvested shares vest only if the company is acquired and the founder is terminated without cause or their role is materially reduced within a defined period. This protects founders against being pushed out by the buyer while keeping their incentive to stay.

Double-trigger acceleration on a portion of unvested shares is a common compromise. The exact percentage and time window are negotiated.

What happens to founder vesting in a funding round

Investors sometimes ask founders to restart or extend vesting when they invest, especially if the founders are already largely vested. Their reasoning: they are betting on the team for the next several years, and fully vested founders have less financial reason to stay.

Common outcomes include:

• Keeping the existing schedule unchanged
• Re-vesting a portion of already vested shares
• Adding a new vesting period for all founder shares with credit for time served

None of these is automatically right. Founders who have already worked several years have a reasonable argument for keeping substantial credit. Understand how any change interacts with dilution from the round itself; the funding dilution calculator shows ownership after the round, and vesting then determines how much of that ownership is secure. The broader process is covered in the startup fundraising guide.

Checklist for your founder vesting terms

• Total vesting period (often four years) and cliff (often one year)
• Vesting frequency after the cliff: monthly or quarterly
• Vesting start date for each founder, including any credit for prior work
• Mechanism: reverse vesting with repurchase right, or another structure suitable for your jurisdiction
• Repurchase price for unvested shares
• Good leaver, bad leaver and any intermediate definitions
• Treatment of vested shares in each leaver case
• Acceleration: single or double trigger, percentage and time window
• Tax steps required at issuance, confirmed with a tax adviser
• Consistency with the option plan used for employees

Common mistakes

No vesting because "we trust each other". Trust is not the issue. Circumstances change: health, family, burnout, a job offer. Vesting handles these situations without turning them into disputes.

Vesting start date left vague. If the start date is not written down, it becomes a negotiation at the worst possible moment.

Bad leaver definitions that are too broad. They can make founders reluctant to leave even when leaving would be better for everyone, or produce outcomes that feel punitive.

Ignoring tax deadlines. Some jurisdictions have strict deadlines around issuing shares that are subject to vesting. Missing them can be expensive.

Copying employee option terms for founders. Founders usually hold shares, not options, and need different mechanics. Employee equity is covered in employee option pool explained.

Getting it done

Agree on the commercial terms among the founders first: period, cliff, start dates, leaver categories and acceleration. Write them in a one-page summary, then ask a startup lawyer to turn them into binding documents that fit your country and company form. It is one of the cheapest pieces of legal work a startup will ever buy, relative to the disputes it prevents.