Pricing
One product, one price, and a free tier that computes real figures rather than teasing them. There is no subscription, because there is no server for you to be renting.
What that buys
- Unlimited portfolios, brokers, accounts and tax years — no per-holding or per-trade limits
- Multiple brokers merged into one Section 104 pool per security, which is what HMRC actually requires
- SA108 box numbers, a disposals CSV, and a computation pack showing every figure's working
- The mapping wizard, for any broker whose export we do not recognise yet
- Manual adjustments: opening holdings, corporate actions, negligible-value claims
- Updates and new tax-year rates, at no further charge
macOS and Windows. Not yet available to buy — offer to test an early build.
Free, and genuinely free
The three tools on this site are not demos. They run the same engine, compiled to WebAssembly, and give the same figures the paid app gives — there is no reduced-accuracy free tier, and no point at which a number is withheld until you pay.
| Free, in your browser | GainPool · £12 | |
|---|---|---|
| Section 104 pooling and matching | Yes — the same engine | Yes |
| 30-day rule verdicts | Yes | Yes, across your whole year |
| Reads your broker's export | Checks whether it can | Imports it |
| Entering trades | By hand, one at a time | From the files your broker already gives you |
| More than one broker in one pool | No | Yes — the reason the app exists |
| Annual exempt amount, rates, losses carried forward | No | Yes, including the 30 October 2024 rate change |
| SA108 box numbers | No | Yes |
| Computation pack, disposals CSV | No | Yes |
| Saved, encrypted sessions | No | Yes |
Why £12, and why once
Because the marginal cost of one more copy is nothing, and because a subscription would be charging you rent for software running on your own machine. There is no server doing work on your behalf between January and the following January — the computation happens on your computer, so there is nothing to meter.
It also settles a question you would otherwise have to ask every year. Capital gains reporting is annual, the deadline is 31 January, and a tool you have to re-buy each season is a tool you will re-evaluate each season. This one you buy once.
What £12 does not buy
Said plainly, because a low price invites the assumption that something is being hidden:
It is not tax advice
We are not accountants. It computes an estimated position from the records you give it.
It does not file anything
Nothing is submitted to HMRC; you type the figures onto your return, or hand the pack to whoever does.
It is not a portfolio tracker
No live prices, no performance charts, no dividend income reporting.
It does not cover everything
Options, futures, CFDs, property and the reliefs are all out of scope — the full list is here, and it is on screen in the app before any figures are shown.
Support is email, from a small company
We will say what our response times actually are before you can buy rather than after.
Refunds
The full terms, the refund window and our support response expectations are published before the product is available to buy, alongside a matrix of exactly which scenarios are supported. We would rather you knew what you were buying than have to ask for your £12 back — but the checker on this site exists so that the most common reason for wanting a refund, "it could not read my file", is something you can rule out for free, in about ten seconds, before paying anything.
Start with the file, not the payment.
Not on sale yet.
The engine is built.
Work in progress covers code signing, licensing and support, ahead of a public release in time for the 2025/26 deadlines. Early builds are available to anyone willing to break them with a real export.
Opens your email app, addressed to us. No list, no newsletter. A person replies.