If a UK trading platform has lately asked you to confirm your date of birth, home address and country of tax residence — and declined to let you carry on until you did — nothing has gone wrong with the account. Per HM Treasury and HMRC’s published consultation outcome, the Cryptoasset Reporting Framework — CARF, the standard for reporting cryptoasset holdings to tax authorities — applies from 1 January 2026, and the UK has extended it to domestic reporting on UK customers, not just cross-border cases. The prompt on the screen is the rule arriving.
The obligation sits on the firm, not on the customer. Reporting Cryptoasset Service Providers — RCASPs, in the government’s shorthand — must identify their users and their transactions, and users are in turn subject to self-certification requirements including tax identification information, per the same document. The fields gathered include name, date of birth, home address and country of residence, with legal business name and main business address where the customer is an entity, as reported by CoinGeek; the government’s own outcome document does not itemise them. The first reports, covering the 2026 calendar year, are due by 31 May 2027 — which is why the nagging is happening now. A firm cannot report what it never collected.
What matters is what being reported is not. CARF is an information rule. It tells HMRC who holds what and who moved it; it does not create a liability, set a rate, or decide whether any given disposal was taxable in the first place. That remains governed by existing rules, on which HMRC publishes its own guidance for people selling cryptoassets. Nobody should read a self-certification prompt as proof they owe something — or as proof they don’t.
Refusal, then. The same CoinGeek report puts penalties at up to £300 per user for inaccurate or incomplete reports; the government’s consultation outcome said only that penalties should be reasonable and proportionate, with detail to follow from HMRC. Treat the figure as reported, not fixed. Either way the exposure is the firm’s, not the customer’s, which is why the request tends to arrive as a blocker rather than a suggestion. Whether platforms should go further and block accounts outright was contested in the consultation, and the government said it would weigh the options — so what yours does sits in its own terms, not in the rules.
It is the direction of travel we traced when the FCA’s market-abuse consultation closed, arriving from a different department. Crypto is being wired into the ordinary machinery of the British state one obligation at a time, and tax reporting is the least glamorous wire of all.
Nothing here is tax or financial advice — take the tax question to HMRC or a qualified adviser, and note that this remains a high-risk market with little FSCS cover behind it.