Acceleration works like this: once the trigger written into the documents fires, the rest of the vesting schedule closes at once, and the unvested equity of the founder and the key team counts as vested from that day. Agreeing the price in an acquisition takes far less work than settling this single clause. Most founders read it for the first time in a diligence list sent by the buyer’s counsel — on the day it bites, not on the day it was drafted.
Acceleration is a shortcut through the reverse vesting schedule. Even where founder shares stand in the founder’s name in the share ledger (pay defteri) from day one, the shareholders’ agreement (pay sahipleri sözleşmesi) and the option plan tie those shares to time and to continued service. If a change of control happens before the schedule has run its course, the unvested portion either passes quietly to the buyer or stays with the founder to the extent the clause allows. That difference decides who the closing proceeds actually reach.
For a group run from Türkiye there is a further layer. The clause is written into the documents of the foreign holding company set up at the investment round, while the person leaving is an employee or shareholder of the Turkish entity. When their shares have to be bought back, the transfer restrictions (bağlam) of the Turkish Commercial Code (Türk Ticaret Kanunu, TTK), employment law obligations and the limits on a company acquiring its own shares all come into play. Acceleration is not an exit detail; it is a decision taken when the plan is drafted.
What does a single trigger really change compared with a double trigger?
Single-trigger acceleration turns on one condition: a change of control. The moment the company is sold, all of the unvested shares, or the portion the clause names, are treated as vested; whether the founder stays on after closing makes no difference. Double-trigger acceleration requires two conditions together: first the change of control, then the departure of the founder or employee within a defined window. If no departure occurs, the schedule keeps running under the buyer’s roof exactly as before.
The distinction sounds technical, and its economics are blunt. A single trigger releases the very team the buyer thought it was acquiring; a double trigger keeps the team tied in while protecting anyone whose employment is terminated. When we meet single-trigger acceleration in early-stage documents, our first question is whether it reflects a deliberate choice or was copied wholesale from a precedent. Market practice leans towards the double-trigger construction. That preference is renegotiated at every round. It has never hardened into a rule.
Either construction is only as sound as the vesting and cliff mechanics beneath it. Where the schedule is loosely drafted, the clause cannot say what is being accelerated, and the argument at closing shifts to how many shares had vested by that date.
The three parties at the table want different things
For the founder and the team the arithmetic is simple: years of below-market cash pay were traded for equity, and the sale is the moment that equity turns into money. If the unvested portion falls away at closing, part of the work done was never paid for.
The buyer buys the team rather than the product. If everyone’s equity vests at closing, the only retention tool left is a fresh incentive package — which means paying part of the price a second time. The buyer’s first instinct is therefore to have the acceleration provisions switched off as a condition of closing.
The party that surprises founders most is the existing investor. Founders tend to assume the investor will stand with them here. Where the sale price depends on the team staying, the investor sits closer to the buyer’s position. The person who has to defend acceleration in a shareholders’ agreement negotiation is the founder, and the most productive time to do it is while nobody is yet thinking about a sale price.
The four details that are actually negotiated
The distance between having the clause and having one that works closes on four points — also the first places we look when reading an acceleration provision.
- Scope. The drafting must say plainly whether acceleration reaches all of the unvested shares or only part of them. Leaving the proportion open does not remove the argument; it postpones it to closing week.
- The definition of departure. In a double-trigger structure, does the second trigger cover only dismissal without just cause, or does it also cover the founder’s own resignation after a material change to role, pay or place of work? Without the second limb, a buyer can reach the same result without dismissing anybody.
- The time window. The period after closing within which the second trigger must occur has to be fixed; with no window at all, the clause either creates an open-ended right or is dead on arrival.
- Who it applies to. Is acceleration granted only over founder shares, or does it run through the employee share option plan as well? Promises made to the team orally but never written into the plan are among the fastest ways to lose trust at closing.
These four points have to be read together with the good leaver and bad leaver distinction built elsewhere in the plan. Where the two documents define departure differently, the provision applied at closing is usually the one that works against the founder.
Where this arrangement lives in Türkiye
In a Turkish joint stock company the acceleration provision lives in the shareholders’ agreement and the option plan, not in the articles of association (esas sözleşme). There is a technical reason: TTK art. 340 allows the articles to depart from the Code’s provisions on joint stock companies only where the Code expressly permits it. Vesting, trigger definitions and acceleration mechanics do not fit inside the articles and stay on the contractual layer.
The practical consequence is that the clause binds only those who sign it. A shareholder who arrives later and was never asked for a deed of adherence sits outside the arrangement. Where the company itself is not a party, it may owe nothing as to what is entered in the share ledger either. The gap that opens most easily is an option plan adopted by board resolution and never reconciled with the shareholders’ agreement. When the two define different triggers, nothing says which prevails.
The definition of a change of control also needs drafting with the Turkish side in mind. Shares in the offshore holding company and shares in the Turkish operating entity do not always change hands at the same moment. If the drafting does not say at which layer the trigger sits, a sale can complete without acceleration ever firing — and the reverse is equally possible.
What happens when a departing founder’s shares are bought back?
The other face of the debate is the return of unvested shares to the company or to the other shareholders. For registered shares, transfer may be restricted through the articles under TTK art. 492. In an unlisted company, art. 493/1 lets the company refuse approval only by relying on an important reason set out in the articles, or by offering to acquire the shares at their real value. Art. 493/2 treats provisions of the articles concerning the composition of the body of shareholders as such an important reason; art. 493/4 confines the company to the real-value offer alone where shares pass by inheritance, division of an estate, the matrimonial property regime or enforcement proceedings. A provision assuming that a leaver’s shares simply revert to the company stays on paper unless it is built around that framework.
If the company itself is to take the shares, the boundary is sharper. TTK art. 379 prevents a joint stock company from acquiring its own shares beyond 10% of its share capital, requires the general assembly to authorise the board, requires the consideration for those shares to have been paid in full, and requires sufficient distributable funds to remain afterwards. If the buy-back price is funded from company resources, the prohibition on financial assistance under TTK art. 380 needs separate consideration. A limited liability company looks different: under art. 595 the transfer of a capital share requires the approval of the general assembly unless the company agreement provides otherwise, and without that approval the transfer does not take effect.
None of these provisions forbids acceleration. They decide who bears its consequences, out of which funds, and in what order. Tying the buy-back to a right of first refusal held by the other shareholders works more smoothly in many structures than a self-acquisition by the company.
By the time everyone is at the sale table, the wording of the acceleration clause is a given; what is negotiated that day is the buyer’s wish to switch it off. The ground is won when the plan is written: the number of triggers, the definition of departure, the length of the window and whether the clause reaches the team all belong in the first draft, the shareholders’ agreement and the option plan should share one set of definitions, and the Turkish buy-back mechanics should be aligned from the outset with the TTK provisions on transfer restrictions and on a company acquiring its own shares. Acceleration is the consequence of a sentence written years earlier.
This article is provided for general information only and does not constitute legal advice. Please seek legal support for an assessment of any specific matter.
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