The Three Year Rule Is Not a Lock: Tokenisation, PISCES and the Truth About SEIS Liquidity

Picture an angel who backed a Leeds founder's seed round eighteen months ago. The company is growing, a later investor has offered to buy some of the angel's shares, and the angel would like to take a little money off the table. There is a worry in the room. Those shares carry SEIS relief, and SEIS comes with a three year holding rule. Does selling now blow up the tax benefit?

For a long time this question got waved away as too complicated, or treated as a genuine unknown. It is neither. The answer matters, because it is the hinge on which the whole case for tokenised seed equity in the UK turns.

The three year rule is a tax condition, not a lock

Start with the part most people get wrong. The three year holding period in SEIS and EIS is a condition attached to the tax relief. It is not a legal lock on the shares, and it is not a restriction the company imposes on the investor. An investor is free to sell SEIS or EIS shares whenever they choose. What happens if they sell inside three years is simply that the income tax relief on those shares is withdrawn, and the capital gains exemption falls away.

The shares were always theirs to move. The relief is the thing with the clock on it.

That distinction sounds small. It is the whole game. Once you see that the three years governs the relief and not the share, the question stops being "are tokenised seed shares trapped" and becomes "how do you design liquidity so that investors who want to keep their relief can, and investors willing to trade it away can move sooner." That is a design problem, and design problems have answers.

Why tokenised shares keep their SEIS status

The second worry is whether wrapping a share in a token disqualifies it in the first place. The most durable model emerging in the UK answers this by changing nothing about the legal share. The company's register of members remains the single legal source of truth, with Companies House filings following as the public record.

The legally issued ordinary shares, paid for in cash and filed in the normal way, are exactly the shares HMRC already recognises for SEIS. The token is a tradable digital representation of that underlying share, with the legal holding sitting in a compliant nominee or custody structure that maps back to the register. None of the qualifying conditions is altered. The share is still an ordinary share, still paid up in cash, still recorded where HMRC expects to find it.

This is the point that gets lost when tokenisation is sold as a way to reinvent equity. The durable version does the opposite. It leaves the equity, the tax treatment and the legal filings exactly where they are, and changes only how the holding can be represented and moved. The conventional allotment filing still happens. The shareholder agreement and the articles carry the tokenisation rules. The relief rides on the underlying share, untouched.

There is honest work still to do, and it is worth naming.

The hardest part is not the token, it is the join. Mapping a fast moving digital ledger to a slow moving Companies House, and to nominee and custody providers built for a paper era, in a way that satisfies both HMRC and the FCA, is a real challenge. That is exactly what live pilots are being built to prove, and it is where the genuine open questions sit. But the principle, that a tokenised ordinary share can retain SEIS status because the legal share underneath it never changed, is in our view, still sound.

What PISCES actually changes

Now bring in the part that makes this more than a tidiness exercise. The traditional bargain in seed investing is brutal on time. An angel puts money in and typically waits seven to ten years for an exit before seeing a penny back. That long wait is one of the quiet reasons early backing can be so scarce, especially for founders without a wealthy network to fall back on.

PISCES, the UK's new framework for intermittent trading of private company shares, changes the shape of that wait. It lets a company open controlled trading windows, on terms the founder sets, where shares can change hands at a valuation that reflects how far the business has actually come. Pair that with tokenised shares and you get something genuinely new at the seed stage. A lock in period, then periodic windows, where an investor can release some liquidity years before any exit, at a value that has moved as the company has grown.

Line that up against the three year rule and the picture resolves. Structure the first meaningful trading window at or beyond the three year point, and a SEIS investor keeps their full relief and gains early liquidity - perhaps access to some gain if the Net Asset Value (NAV) of the business has increased since that first raise.

The realistic horizon for getting money back now compresses from the traditional seven to ten years down to as little as three. For an investor weighing whether to back an unproven founder, that is a different proposition entirely. And because earlier liquidity makes backing founders more attractive, it widens the pool of people willing to do it. That is the founder access argument, arriving through the back door of a tax rule and a trading window.

Two honest caveats hold this together. Liquidity is enabled, not guaranteed. A trading window only matters if there are buyers, and that depends on the company being worth buying into. And an investor who chooses to sell before three years still forfeits the relief on those shares, by choice, with eyes open. The model does not abolish the trade off. It makes it visible and lets the investor decide.

The question we are putting to the room

So the three year question has an initial answer, and it is more encouraging than the usual hand wringing suggests.

• Selling early does not break any rule, it forfeits the relief.

• Tokenised shares can keep their SEIS status when the legal share underneath is left conventional.

• And tokenisation paired with PISCES can pull the liquidity horizon in from a decade to a few years without anyone losing something they were entitled to.

What is not yet settled is the plumbing, and that is where we want the conversation.

Q. How should a tokenised ledger reconcile with Companies House in practice?

Q. What nominee and custody structures keep both HMRC and the FCA comfortable?

Q. What would good HMRC guidance say, so that founders and angels do not have to reason it out from first principles every time.

We would like to hear from venture tax specialists, digital securities lawyers, the PISCES operators, custody providers, and the founders and angels already testing this in live rounds. Tell us where this holds, and where it breaks.

Key takeaways

• The SEIS and EIS three year period is a condition of the tax relief, not a lock on the shares. An investor can sell sooner and simply forfeits the relief on those shares.

• Tokenised seed shares can retain SEIS status when the underlying ordinary share is issued and filed conventionally, with the register of members remaining the legal source of truth.

• The real technical challenge is reconciling a tokenised ledger with Companies House and with nominee and custody providers, which live pilots are being built to prove.

• Tokenisation paired with PISCES trading windows can compress the realistic liquidity horizon from seven to ten years down to as little as three, without sacrificing relief.

• Liquidity is enabled, not guaranteed, and an early sale still forfeits relief by choice. We are inviting the experts to pressure test the model.

This article is general information and an open editorial discussion, not tax or investment advice. It describes how SEIS and EIS rules interact with emerging tokenisation and PISCES models, and flags clearly where structures are still being proven in pilots and where HMRC has not issued specific guidance. Anyone making decisions about SEIS, EIS, tokenised shares or PISCES should take professional advice.

Sources: HMRC Venture Capital Schemes guidance (gov.uk); British Business Bank SEIS guidance; FCA PISCES materials and operator approvals; Finance Act 2026 changes to EIS and VCT limits.