HMRC sent 81,172 warning letters, emails and texts to crypto holders it suspected of underpaying tax in the 2025-26 tax year, up from 27,714 two years earlier (Accountancy Age, 2026). Those letters were built on fragments of data. From 1 January 2026 the fragments stop, because UK crypto platforms are now legally required to collect your identity details and report your transactions to HMRC directly.
TL;DR: From 1 January 2026, UK cryptoasset service providers must collect your name, date of birth, address and tax reference, then report your transactions to HMRC. The first reports are due between 1 January and 31 May 2027 and cover the whole of 2026. Give a platform inaccurate details, or none, and the penalty is up to £300.
What Changed on 1 January 2026?
UK cryptoasset service providers now have to run due diligence on every user, tell that user their data will be shared, and report it to HMRC. The rules come from the OECD's Cryptoasset Reporting Framework, brought into UK law by the Reporting Cryptoasset Service Providers (Due Diligence and Reporting Requirements) Regulations 2025 (legislation.gov.uk, 2025).
The reports include your identifying details and a summary of your transactions. Providers must file their first report between 1 January and 31 May 2027, covering 1 January to 31 December 2026, then by 31 May each year afterwards for the previous calendar year (GOV.UK, 2026).
So the trades you are making right now sit inside the first reporting period. There is no grace year.
Does This Apply If You Only Use a UK Exchange?
Yes, and this is the part most coverage misses. The international framework only obliges a provider to report users resident abroad. Left alone, a UK resident using a UK platform would have fallen through the gap.
The UK closed it. Following Royal Assent to Finance Bill 2025-26, UK providers must report information on UK-resident customers to HMRC as well, in force from 1 January 2026. HMRC's stated aim is to hold data on all UK taxpayers using both UK and non-UK platforms, and it estimates around 50 UK providers are caught (GOV.UK policy paper, 2026).
Use a platform based overseas and you are not outside the net either. It reports to its own tax authority, which passes the data to HMRC under the exchange agreement.
The Gap Between What Is Held and What Is Declared
HMRC published its first breakdown of declared crypto gains on 27 August 2026, and the numbers are worth sitting with. Just 17,600 taxpayers declared cryptoasset disposal proceeds of £13.8 billion, producing £1.38 billion of gains. Within that, 240 people each declared more than £1 million, totalling £717 million (GOV.UK, 2026).
Set 17,600 declarations against the Financial Conduct Authority's finding that roughly 8% of UK adults hold cryptoassets, about 4.5 million people (FCA, 2025). Not every holder makes a taxable disposal in a given year. But the gap is wide enough to explain why the letter count keeps climbing.
What we see most often is confusion rather than evasion: someone swapped one token for another, never took a pound out of the exchange, and had no idea a tax point had occurred.
What Information Must You Give Your Platform?
If you are an individual, you need to supply your full name, date of birth, residential address and country, and your tax identification number, which for a UK resident means your National Insurance number or UTR. Companies, partnerships, trusts and charities give the legal business name, main business address, company registration number, and for non-UK entities a tax identification number and country of issue. Some entities also have to give details of controlling persons (GOV.UK, 2026).
You give it through the platform's own identity or self-certification process, usually a form in your account settings that the provider prompts you to complete. You have to do this for every provider you use, including ones not based in the UK.
The penalty for giving inaccurate details, or none, is up to £300, and HMRC says it can be higher where a non-UK provider is involved. Providers face their own penalty of up to £300 per user where they fail to obtain a valid self-certification, so expect them to keep asking until you respond.
Which Crypto Transactions Actually Create a Tax Bill?
Four things count as a disposal: selling tokens for pounds, exchanging one cryptoasset for another, using tokens to pay for goods or services, and giving them away to anyone other than your spouse, civil partner or a charity (GOV.UK, 2026).
Gains above the annual exempt amount of £3,000 are charged at 18% where they fall in the basic rate band and 24% above it, for gains from 6 April 2026 (GOV.UK, 2026). If you already file a return, you also have to report disposals where total proceeds exceed £50,000 in the year, even when no tax is due.
Rewards are different. Staking, mining and most airdrop receipts are taxed as income at the point of receipt, not as gains. And if your limited company holds the tokens, the charge is corporation tax on chargeable gains rather than Capital Gains Tax.
What Should You Do Before the First Report Lands?
Reconcile 2026 while the data is still easy to get. Exchanges change ownership, shut down, and lose historic export functions, so a January 2027 scramble for a full year of history is a bad place to start. When we pull a client's history together, the hold-up is almost always a platform they stopped using years ago and can no longer log into.
Work through it in this order:
- Export the full transaction history from every platform and wallet you used in 2026
- Check the name, address and tax reference each platform holds matches your HMRC record
- Calculate gains using HMRC's share pooling rules for tokens, including same-day and 30-day matching
- If you had gains in 2025-26 and do not already file a return, register for Self Assessment online through GOV.UK by 5 October 2026
- File and pay by 31 January following the end of the tax year
Self Assessment returns have carried a dedicated cryptoasset section since 2024-25, so there is a specific box to complete rather than a note in the white space. If filing is new to you, our guide on registering with HMRC for a side income covers the process.
What if earlier years were wrong?
Use HMRC's voluntary disclosure service for cryptoassets on GOV.UK. You pay what you owe for 4 years if you took reasonable care, 6 years if you were careless, and up to 20 years if the underpayment was deliberate. Payment is due within 30 days of receiving your reference (GOV.UK, 2026). Coming forward before HMRC contacts you generally reduces the penalty, the same logic that applies to HMRC nudge letters on rental income.
Frequently Asked Questions
Does HMRC see the crypto in my own private wallet?
A self-custody wallet is not a reporting provider, so nobody files a report on the wallet itself. But the moment tokens move to or from an exchange, that platform records the transfer and reports it. In practice HMRC sees the entry and exit points and can ask you to explain what happened in between.
I lost money on crypto in 2026. Do I still need to do anything?
Report the losses if you want to use them. You claim them on the capital gains pages of your Self Assessment return, or in writing to HMRC if you do not file one, usually within four years of the end of the tax year in which the disposal happened. Once claimed they carry forward against future gains indefinitely, so a year of losses recorded now is worth real money against a later gain.
My limited company holds tokens on its balance sheet. Are we in scope?
Yes. Your platform has to collect the company's legal name, registered address and company number, and report the entity in the same way. The tax charge on disposals sits within corporation tax, and the tokens need proper treatment in the year-end accounts rather than a note at the bottom.
Will this change how much tax I pay?
No. The rules on what counts as a disposal and the rates that apply are unchanged, and the 18% and 24% Capital Gains Tax rates are the same ones that apply to shares. What changes is HMRC's ability to check your return against the platform's own record of what you did.
If you hold cryptoassets personally or through a company and have not reconciled your 2026 position, get in touch. We will work through your transaction history, calculate where you actually stand, and tell you plainly whether a disclosure for earlier years is worth making before the first reports reach HMRC.