Why is my crypto tax number too high?

When a disposal cannot be matched to an acquisition, the cost basis defaults to zero and 100% of the proceeds are reported as profit. Nothing fails and no error is raised — the number is simply wrong, in the taxman's favour. On one reference dataset of 7 wallets and roughly 30,000 records, a leading incumbent reported a £336,248 gain where the reconciled position was a £176,494.84 loss.

Does Finality file my tax return?

No. Finality computes the figures and produces a box-mapped working paper for SA108 plus an evidence workbook. You own the return and file it yourself. Finality is software: it is not a firm of accountants, not a regulated tax adviser, and not affiliated with or endorsed by any tax authority.

Does Finality support tokenised equities and real-world assets (RWAs)?

Yes. A tokenised equity, tokenised stock, tokenised treasury bill or gold-backed token is an ERC-20 transfer on the same chains, so the same engine reads it, prices it by contract, pools it under Section 104 and matches its disposals to the acquisitions that paid for them. There is no separate RWA mode and no allowlist of supported tokens. What the engine does not do is decide what an asset is for tax — a token representing a share may be a security rather than a cryptoasset, and that is put to you as an open question.

How are NFTs treated differently from fungible tokens?

HMRC applies no pooling and no matching rules to non-fungibles (CRYPTO22200) — each is specifically identified. Running a non-fungible through the pooling engine would pool what must never be pooled and apply rules HMRC excludes, so they are handled by a separate engine.

What does Finality cost?

A tax year is bought once, not subscribed to: £20 up to 1,000 transactions in the filing year, £40 for 1,001–10,000, and £60 beyond that (a US filing year is $25, $50 or $75). Every prior year of history the computation needs is included at no extra charge, because cost basis is cumulative. Scanning is free and shows every finding and its value; the corrected figure, the working paper and the evidence workbook are what is paid for.

Does Finality need my exchange API keys?

No. Finality does not accept exchange API keys at all. You upload the CSV export from your exchange instead, so there is no credential to store. Sign-in does not use your wallet either — there is no message to sign and no transaction to approve.

What we store, and what we can never touch

Your wallet set is a complete picture of your financial life on-chain. That is exactly why the product is built so that holding it gives us no power over it.

What we hold

Your email, and passkeys if you add them

Wallet addresses you declare — public information you choose to associate

CSV exports you upload — the transactions themselves, never a credential that could fetch more

The raw source data behind your computations, so recomputation never re-queries and your evidence never changes under you

What we never hold

Private keys or seed phrases — the product has no field to paste them into

Funds. We custody nothing and can initiate no transaction of any kind

Exchange API keys of any kind — this build does not accept them at all, so there is none to leak

Your addresses shared with any third party without your explicit consent

Deletion is deletionDeleting your account removes wallets, keys, raw data and computations, completing within 30 days. We offer a full export first.

DeterminismSame inputs, same outputs, byte for byte. Your figures cannot drift between runs, and every figure traces to source rows.

We do not take exchange API keys at all

Exchanges are handled by uploading their CSV export. You download your own transaction history and give us the file. There is no credential to store, nothing that could be used to fetch more than you handed over, and nothing to leak.

This was a deliberate cut. A read-only key still exposes a complete trading history, and holding one would be worth doing only if the key bought something the file does not. It does not: an imported row is pooled exactly as a fetched one is, because the same asset is the same Section 104 pool whatever route it arrived by. What a key would save is one download.

The instructions for getting the file out of each exchange are in the product, on the screen where you upload it — including the one thing that actually matters, which is asking for your full history rather than a single tax year. A year-filtered export leaves out the purchases that carry your cost basis, and that does not produce an error. It produces a gain that is too high.

Sign-in does not use your wallet

Email link or passkey. Never a wallet signature — it proves control of a key, not who you are, and it is the wrong instrument for a tax product.

The site and the product are separate origins

Marketing runs on one host and the product on another. The product host carries a strict content-security policy, runs no third-party scripts at all, and is closed to crawlers. A compromised vendor script on the marketing site cannot reach product session state, because it is a different origin with a different cookie jar.

How the encryption works, and what it is not

Nothing is encrypted here today, because there are no exchange credentials to encrypt. The machinery exists and is described anyway, so that the day anything is sealed the limits are already on the record rather than written afterwards to flatter.

What it does when it is used: a data key unique to your account, wrapped by a key the database never holds, sealed with AES-GCM— the standard, reviewed cipher, which replaced a hand-rolled construction. What is not right yet is the wrapping key. It is a file on the same server, not a managed key service, so anyone able to read that filesystem could unwrap whatever it protects. No hardware boundary, no audit trail of decrypt calls, no rotation.

We would rather say this than let “encrypted” do work it has not earned. It is also why this build takes no exchange API keys: the honest response to storage we would not stake a trading account on is not to hold the credential at all.

What we do not yet have

No third-party assurance report yet

We do not hold a SOC 2 Type II report or ISO/IEC 27001 certification. When we do, they will be named here with their scope and date. Until then this page is the whole of our security position, and we would rather state that plainly than imply otherwise.