Part-time and academic co-founders

1. Core idea and who it's for#

Deeptech companies often start with someone who cannot or will not go full time yet. This might be a professor whose lab produced the invention, a clinician who sees the patients, or an industry engineer who will not leave a salary until there is funding. These people can be essential. The problem is not that they are part time. The problem is giving them full-time founder terms and calling them co-founders on the cap table, without saying so or agreeing what happens next.

This playbook covers how to:

1. Name the role honestly. Is this a part-time co-founder on a real path to full time, or a scientific founder or adviser who will stay part time?
2. Price equity by time and risk, not by the importance of the original idea. The idea's value is usually paid for separately through the licence (2.07, 2.08).
3. Write in triggers. Agree the dates or milestones by which they go full time, and what happens to their equity if they don't.
4. Stay inside their employer's rules, such as university conflict-of-commitment limits, IP policies and day-job contracts.

Who it's for: full-time founders working with an academic or part-time partner, and academics deciding how to be involved in a spinout from their own lab. It pairs with 1.03 (leave, sabbatical or dual role) and 2.12 (professor as co-founder, adviser or CSO), which cover the academic's side of the decision.

The one-line rule: equity follows commitment, so write down the commitment, the date it rises, and what happens to unvested shares if it doesn't.

2. Evidence#

Most investors treat part-time founders as a red flag. Allied Ventures, for example, says it requires every co-founder to be full time before it invests, and sees a founder who will only go full time once funded as a non-starter. Chris Neumann says non-full-time founders almost always make investors pause. CRV notes that vesting, equity and due diligence all assume full-time work as the baseline.

Large stakes for part-timers are the specific worry. Investors list passive co-founder shares and big stakes held by non-operating advisers as cap table problems. Ash Rust of Sterling Road argues that founders should not give an academic adviser a big stake,

because career academics almost never go full time. In a TechCrunch piece, one investor describes the pattern of academic founders who drop in and out with advice while others do the work.

Deeptech is the exception that proves the rule. Investors in science spinouts often accept a part-time scientific founder, as long as there is at least one full-time operator. They want the academic's equity sized to their real role, and the rest of the team clearly committed. One spinout commentator suggests 5 to 6 year vesting with a 1-year cliff for academic co-founders.

University rules limit how much time academics can give. Many US universities cap outside work at about one day a week, around 20% of time:

• Columbia: roughly 20% time, one day a week
• Yale: no more than one day per seven-day week
• Brown: one day a week, on average, but not during unpaid summer months for 9- month faculty

India's National Innovation and Startup Policy (NISP 2019) says faculty in an executive role for more than 3 months should take a sabbatical or leave. It allows faculty to hold equity in a startup while spending up to about 20% of their time on it (see 1.03). UK universities usually allow a set number of consultancy days a year and need approval for directorships.

This means the time limit is often not the founder's choice. A professor who "wants to help more" may simply not be allowed to. Building the plan around the real limit avoids disappointment and breaches of their employment contract.

3. Method#

Step 1: Put them in one of three boxes#

These ranges are rules of thumb from practice, not survey data. 2.11 (spinout equity norms) and 2.12 cover the academic case in more depth.

Step 2: Write down the commitment#

Spell out days per week, what they own (for example, technical direction and grant applications), how fast they respond, and their employer's limits. A one-page "commitment schedule" attached to the founders' agreement (3.07) avoids arguments later.

Step 3: Tie the equity to commitment#

You have three main tools, and you can use them together:

1. Two-tranche vesting. A smaller tranche vests over 4 years from now. A larger tranche only starts vesting when they go full time, and lapses if they haven't by a deadline.
2. Trigger-based vesting. Vesting speeds up when a defined event happens, such as a priced round, leaving the university or a key grant. It slows down or stops if the time commitment drops.
3. A going-full-time deadline. If they haven't gone full time by the agreed date (often the seed close or 12 to 18 months), their unvested shares go back to the company. Make this an agreed outcome, not a dispute.

Step 4: Separate the idea from the person#

In a university spinout, the university is paid for the IP through the licence and its own equity (2.08, 2.11). The inventor's personal stake should reflect their future role, not repeat payment for the invention. Saying this openly takes the emotion out of the split.

Step 5: Protect the full-timers#

• The full-time founders hold the majority of votes and board seats.
• Part-time founders should not have a veto over operational decisions.
• Put in a clear process for changing roles later (3.16), and good/bad leaver terms (3.12).

Worked example (illustrative)#

A UK battery-materials spinout has three people:

• Dr A: a full-time CEO, previously a postdoc in the lab.
• Prof B: the PI and inventor, allowed about one day a week.
• Ms C: a process engineer at a chemicals company. She will go full time once the seed closes.

The university takes 10% through its licence deal. Founders and the pool share the remaining 90% before any investment.

Seed investors see one full-time founder with a clear majority, a second operator who is committed through a trigger, and an inventor whose stake fits their role. Ms C goes full time at month 10 when the seed closes, and her 15% starts vesting. If the round had slipped beyond month 15, her 15% would have returned to the pool. She would have kept her 5% tranche, and the team would have had a planned conversation, not a fight.

4. India, US and UK differences#

India#

• University and institute rules: under NISP 2019, faculty can hold equity and work on a startup within roughly 20% of their time. An executive role for more than about 3 months normally needs a sabbatical or leave, usually up to a semester or a year. Institute rules vary. IIT Delhi, for example, only allows more than one day a week while on leave. Get the institute's written approval before signing a founders' agreement.
• Institute equity: NISP caps the institute's stake at 9.5% or 20% of the faculty member's shares, whichever is lower. This affects how much equity is left for the founders.
• Government employees and labs: scientists at CSIR, DRDO or ICAR labs, and at public sector companies, usually need specific permission to hold equity or a directorship.
• Mechanics: a part-time co-founder can hold shares like any founder. Vesting is not a legal concept for shares in Indian companies, so it is built through a shareholders' agreement (reverse vesting with a buyback or transfer at nominal value). Milestone triggers work the same way.

US#

• Conflict-of-commitment limits: many universities cap outside work at about one day a week, and require disclosure and conflict-of-interest management if the professor's lab does sponsored work with the company (2.14). Many also prevent faculty from holding a full-time or executive role in a startup while on appointment.
• Federal funding: if the company applies for SBIR or STTR grants, the principal investigator must normally be mainly employed by the company for SBIR (more than 50% of their time), while STTR allows the PI to be at the university. This often decides whether a professor or a full-time founder is the PI.
• Mechanics: restricted stock with an 83(b) election. Milestone and time-commitment vesting are written into the stock purchase agreement.

UK#

• University rules: most universities allow a set number of consultancy days a year and require approval for directorships and shareholdings. Spinout policies set the university's stake (2.11). Check whether the academic's time is "bought out" through a consultancy agreement with the university.
• Tax: if a part-time founder is also an employee or director, shares acquired below market value can be taxed as income. Sign a s431 election when the shares are issued.
• EMI: options under EMI need the holder to work at least 25 hours a week, or 75% of their working time, for the company. Part-time academics usually don't qualify, so they get shares or unapproved options instead.
• SEIS and EIS: check the connected-person rules if a part-time founder also invests.

5. Scripts, mistakes and related playbooks#

Scripts

To a professor, setting expectations:

"We want you deeply involved. You're the reason this works. Your university allows about a day a week, so let's build your role around that: technical direction, the grant strategy and the science board. Your equity should match that role, and it can grow if your role does."

To a part-time co-founder, agreeing the trigger:

"I'm happy to start with you part time. What I need is a date. If we close the seed, you go full time within a month, and the bigger part of your equity starts vesting then. If we're not there in 15 months, we keep your first tranche and talk about the right role."

To an investor asking about the part-timer:

"Prof B is our scientific founder at one day a week, which is her university's limit. Her stake is 8% with 5-year vesting. Dr A and Ms C are full time and hold the majority. Ms C's larger tranche only vests because she is now full time."

Common mistakes#

1. Equal splits with a part-timer. If one founder works full time and another works one day a week, an equal split creates resentment and a cap table problem.
2. No deadline for going full time. "When we raise" is not a deadline, and it can drift for years.
3. Paying twice for the idea. The university is paid through the licence. The inventor's stake should be for their future role.
4. Ignoring the employer's rules. Breaching conflict-of-commitment limits or day-job contracts can put the founder's job and the company's IP at risk.
5. Giving part-timers vetoes. A part-time founder with a veto over hiring or spending slows the company down.
6. Letting the part-timer be PI on the wrong grant. For SBIR, the PI's main employer must normally be the company.
7. Not revisiting. Review the arrangement every 6 months, and change the role, title or vesting by agreement if the time given has changed.

Related playbooks#

• 1.03 Leave, sabbatical or dual role
• 2.11 Spinout equity norms
• 2.12 Professor as co-founder, adviser or CSO
• 2.14 University labs after spinout; SRAs
• 3.05 Splitting founder equity
• 3.06 Founder vesting, cliffs and acceleration
• 3.07 Founder agreements: roles, decisions, deadlocks
• 3.09 Adding a co-founder late or after a round
• 3.12 Co-founder breakups: buybacks and good/bad leaver terms

Sources#

• Allied Ventures, How to assess founders during due diligence
• Chris Neumann, Things that make you go hmmmm
• CRV, What is a co-founder?
• Startup Istanbul, Red flags
• Ash Rust, Don't give your professor 20% of your company
• TechCrunch, Sometimes you need to cut your startup's school ties
• Edunomix, Brilliant science, empty chair
• Columbia University, Outside interests and employment
• Yale University, External professional activities guidance
• Brown University, Outside professional activities for faculty

This playbook is general information, not legal or tax advice. University and employer rules vary and change, so check the current policy and get written approval. Last checked November 2026.