No sourced benchmark prices technical co-founder equity for someone who joins after the MVP exists, and the one principled view we found, equal or near-equal founder splits, isn't written about late joiners. So the number matters less than the structure around it: what vests, from which date, and whether the stake comes as shares or options. This guide is for a non-technical founder-CEO deciding what to offer, or a CTO weighing an offer to join late. It's one of our Startup CTO guides: leadership, diligence and the first hires.
This is general information, not legal or tax advice; have a lawyer in your country draft the agreement.
What counts as a late technical co-founder?
Someone who joins after an MVP, an agency build or the first customers exist, and who takes a founding stake rather than a salary and a job title. That separates them from a founding engineer, who is paid and holds options. Option schemes for a paid founding engineer are covered separately.
It also assumes you've already decided you want a partner. If you haven't, read whether you need a technical co-founder at all first. This page starts at the negotiation.
What does the data say about the size of the stake?
Less than you'd hope.
Y Combinator's Michael Seibel argues for equal or close-to-equal splits among founders. He rejects "I brought on my co-founder after launching my MVP" as a reason for a big gap, and writes that small variations in year one don't justify massively different splits over years two to ten. His reasoning is that it takes 7 to 10 years to build a company of great value. That's one respected view, not a consensus, and it's written about founders in general rather than late joiners specifically.
Index Ventures gives one CTO benchmark in its equity handbook: about 1% in the US and 0.7% in Europe at Series A or B (Index measures executive grants against fully diluted equity), which it attributes to more tech-enabled businesses in Europe. Two cautions. This is a hired, non-founding CTO, a different role, so it is a reference point for what an executive hire gets, not a floor or a target for a co-founder. And the page ties the figure to no sample or date, though the handbook as a whole draws on 4,000+ option grants across 200+ startups, a survey of 53 European startups and interviews at 27 Index-backed companies.
We didn't find a sourced percentage for a co-founder who joins at the MVP stage. Blog posts that offer one (ratios, ranges by stage) don't show their data, so we haven't used them. In our judgment, the gap between a day-one founder and a late one is a negotiation, and the inputs to it are below.
What should drive the number?
This table is judgment, not data. It lists what to weigh, and which way each factor pushes.
| Factor | Pushes the stake up | Pushes the stake down |
|---|---|---|
| What exists when they join | Little: they build the first version | A working product, paying customers, revenue |
| Cash risk taken | Salary cut or unpaid months | Market salary from day one |
| Role | Technical lead with CEO-level judgment, owns hiring and architecture | A builder executing a defined roadmap |
| Prior work contributed | Code or IP they bring and assign to the company | Starting from your repository |
| Investors' view of the cap table | Investors expect a technical founder on the table | A late, large grant that dilutes the founding team awkwardly |
Seibel's counter-view applies to every row: if the person will be around for years, a gap built on a year-one difference may not be worth the resentment it creates. Weigh that against the table rather than ignoring it.
How do you price the ask against cash?
Start from the method in our technical co-founder decision guide: compare the equity with what the same work costs in cash. HighCircl senior engineers run EUR 45-105/hr (USD 50-115/hr), with no equity and no minimum hours.
An illustration, with both assumptions ours and flagged. Say you'd need about 20 hours a week of senior engineering for 46 weeks. That's 920 hours. At a mid-range EUR 75/hr, the year costs EUR 69,000 in cash. Now assume the company is worth EUR 3 million at the point of the grant (an assumption, not a benchmark). A 10% stake would be worth EUR 300,000 on paper, more than four times the cash price of one year's work, though the stake would vest over several years of work, not one. The same assumed valuation makes 1% worth EUR 30,000.
The paper value isn't a cost today, and it might end up worth nothing, or far more. But it gives you a sanity check. If the stake you're drifting toward is many multiples of a year of cash for the same work, you're paying for something beyond the work: long-term commitment, shared risk, a partner in the room. That can be worth paying for. Decide it on purpose.
How should a late joiner's vesting work?
The full vesting and agreement checklist lives in the vesting and co-founder agreement checklist. Only the late-joiner differences are here.
The common starting point is four years of vesting with a one-year cliff. Seibel describes it as 25% at one year, then 1/48 monthly. Orrick's founder FAQ cites the same four years with a 12-month cliff as typical for a German GmbH.
For a late joiner, our judgment is that the vesting clock should start at signing. The exception is an earlier agreed date, if trial or contract work is being credited. Backdating vesting to the day they first touched your code gives them a stake for risk they weren't carrying yet. Credit for prior paid work is a negotiation point, so settle it in writing.
Agree good and bad leaver terms up front. Orrick describes a bad leaver as typically fraud, gross misconduct or similar bad faith, with a good leaver covering any other circumstances and an optional grey tier in between. A late joiner who leaves in month nine because the company changed direction should not be treated like one who walks away with the code.
Index adds that in Europe vesting often runs in monthly, quarterly or annual steps, and recommends back-loaded schedules for retention (it gives 10/20/30/40 over four years as an example).
Shares or options for a late technical co-founder in Europe?
The legal form changes what vesting means in practice, and it differs by country.
In Germany, per Orrick, a GmbH founder's shares can vest only if that's agreed contractually in a vesting agreement. The usual mechanism is reverse vesting: the founder remains the registered holder with voting rights, and the company holds a call option to reclaim unvested shares if they leave. Without that contract, the shares are not subject to vesting at all.
In the UK, the Enterprise Management Incentives scheme sets an employment test. HMRC's Employee Tax Advantaged Share Scheme manual says the employee must spend at least 25 hours a week working for the company or, if their working time is less than that, 75% of it, with hours averaged. It also sets an individual limit: options over shares worth GBP 250,000 in total, valued at grant. A co-founder who keeps a day job and builds the product in the evenings may fail the working-time test. We say "may" on purpose. Whether a specific person qualifies is a question for a UK tax adviser before you promise anyone EMI options.
For France, Germany's tax-advantaged route and Poland, we're pointing, not explaining: the sibling article on option schemes for a paid founding engineer covers them.
Our judgment: a founder-level stake is usually shares with reverse vesting, because it gives the holder the rights of an owner from day one while the company keeps a way back. Options suit a smaller grant, closer to what an early senior hire gets. If you're wavering between the two, the stake is probably smaller than founder level.
What this means for your cap table decision
Price the cash alternative first, then decide the stake. Work out what the same engineering would cost over a year, as above, and write it next to the percentage you're considering. If the number you reach is well above a year of cash for equivalent work, test a paid engagement before you grant anything. A paid trial of about four to six weeks (the range our vetting guide cites from NYU's entrepreneurship team) tells you more about fit than a negotiation does, and that guide covers how to run it.
Then grant in steps. Vesting from signing, a cliff, leaver terms, and shares or options chosen for the stake's size. If you're the CTO on the receiving end, ask for the same: it protects you as much as the founder, because a stake that's clearly earned is harder to dispute.
If you'd rather keep the cap table clean for now, a fractional arrangement buys leadership without a permanent claim; what a fractional CTO costs in Europe shows the price.
Hiring senior engineers through HighCircl
If the arithmetic says buy the work in cash, HighCircl matches senior engineers from 7 European countries (6 EU plus Serbia). A shortlist of three to five arrives within 72 hours. Rates run EUR 45-105/hr (USD 50-115/hr), with no subscription, no recruitment fee and no minimum hours. The engineer holds no equity, so your cap table stays as it is. See founding engineers through HighCircl.
FAQ
How much equity should a co-founder get?
We found no sourced benchmark for a co-founder who joins late. Y Combinator's Michael Seibel favours equal or close-to-equal founder splits and treats joining after the MVP as a weak reason for a big gap. Index Ventures' one figure is for a hired CTO (about 0.7% in Europe at Series A or B), a different role. Use the factor table above and price the cash alternative.
Should cofounders be 50/50 or 51/49?
Seibel's position is equal or close to equal. In our reading, a 51/49 split is within that. In our judgment, a one-point edge buys little: control comes from the decision rights, board seats and deadlock process in the agreement, not from one percent. If you want a tie-breaker, write it in.
Is 1% equity a lot in a startup?
It depends on the fully diluted base and the valuation, and we have no sourced benchmark for what counts as a lot. The arithmetic is simple: at an assumed EUR 3 million valuation, 1% is worth EUR 30,000 on paper, and the same percentage means more or less at other valuations. Compare it with what the work would cost in cash.
Should a late co-founder's equity vest?
Yes, in our view. Y Combinator and Orrick both describe four years with a one-year cliff as typical, and in a German GmbH vesting only exists if it's agreed contractually. Start the clock at signing, or an earlier agreed date if trial work is credited, and agree leaver terms at the same time.