Tax — New for 2026
CARF
Reporting.
Since January 2026, crypto exchanges operating in the UK must collect and report your data to HMRC. It's called CARF — the Crypto-Asset Reporting Framework. Here's what it means for you.
Key dates
Exchanges began collecting user data
Exchanges submit 2026 calendar year data to HMRC
Participating in automatic information exchange
What CARF is
CARF is an international framework developed by the OECD for automatic exchange of crypto transaction data between tax authorities. Think of it as the crypto equivalent of CRS (Common Reporting Standard), which banks have used for years to report account information across borders.
The UK adopted CARF through the Cryptoasset Reporting Framework Regulations 2025. These came into force on 1 January 2026. The UK was among the first wave of countries to implement it.
What exchanges report
Any platform that facilitates crypto transactions and operates in (or has UK users in) scope must report. This includes centralised exchanges, brokers, and certain DeFi front-end operators.
They report the following about each user:
| Data Point | Detail |
|---|---|
| Full name | As per KYC verification |
| Address | Registered address on account |
| Date of birth | As per identity documents |
| Tax identification number | National Insurance number for UK users |
| Transaction types | Purchases, sales, swaps, transfers |
| Transaction values | Gross proceeds and cost basis where available |
| Asset types | Which tokens were traded |
What HMRC receives
HMRC receives aggregated annual reports from every in-scope exchange. They also receive data from overseas exchanges about UK-resident users through bilateral exchange agreements.
Here's the thing: HMRC can cross-reference this data with your Self Assessment return. If you reported £2,000 in crypto gains but your exchange data shows £40,000 in disposal proceeds, expect questions.
The first exchange of data with HMRC is due by May 2027, covering the 2026 calendar year. From then on, it's annual.
What you need to do
You don't need to file anything extra specifically for CARF. The reporting obligation falls on the exchange, not you. But CARF does change the game in three ways:
Keep accurate records. HMRC will know what you traded. Your records need to match. Keep transaction histories, download CSV exports from your exchanges, and track your cost basis.
Report honestly.The era of hoping HMRC won't notice your crypto gains is over. If you owe tax, report it. The penalties for non-disclosure are significant — up to 200% of the tax owed in the most serious cases.
Verify your exchange details. Make sure your name, address, and National Insurance number on your exchange accounts are correct and match your HMRC records. Discrepancies can trigger investigation.
Timeline
January 2026: Exchanges began collecting data under CARF regulations. If you opened or used an account from this date, your data is being recorded.
May 2027: Exchanges submit their first annual reports to HMRC, covering all 2026 activity. HMRC begins receiving data from partner countries around the same time.
Ongoing: Annual reporting continues each May for the preceding calendar year. The framework is designed to be permanent.
Disclaimer
This is not financial advice. CARF regulations are new and may be updated. Consult a qualified tax adviser for guidance specific to your situation.
Last updated: March 2026