HMRC and Your Crypto: CARF 2026 Explained — Plus the Best Exchanges for UK Tax Compliance

What Is CARF and Why Should UK Crypto Users Care?

CARF stands for Crypto-Asset Reporting Framework, a global tax transparency standard developed by the OECD and modelled on the Common Reporting Standard (CRS) that already governs bank accounts across 100+ jurisdictions. The UK legislated its implementation through the Finance Act 2024 and the Reporting Cryptoasset Service Providers (Due Diligence and Reporting Requirements) Regulations 2025, which came into effect on 1 January 2026.

In plain English: UK crypto exchanges, custodial wallet providers, and crypto-to-fiat platforms — collectively called Reporting Crypto-Asset Service Providers (RCASPs) — must now collect detailed information about every user and every transaction. The UK is among approximately 48 countries implementing CARF from 2026, with 75 nations globally committed to the framework. That includes all EU member states, Switzerland, the Cayman Islands, and most major crypto hubs. The US is expected to follow in 2028.

Why does this matter to you as a user? Because the era of "HMRC won't know" is definitively over. Whether you profit from a bull run, earn staking rewards, or simply swap one token for another, that activity is now part of a structured data pipeline flowing directly to the UK tax authority.

What Data Does HMRC Actually Receive?

Under CARF, exchanges are required to collect and report the following:

Your identity:

• Full legal name
• Date of birth
• Residential address
• Country of tax residence
• UK Tax Identification Number — your National Insurance (NI) number or Unique Taxpayer Reference (UTR)

Your transactions:

• All crypto-to-fiat conversions (buying or selling for pounds)
• Crypto-to-crypto exchanges (swapping ETH for BTC, for example)
• Transfers between wallets — including to external addresses not linked to another regulated provider
• Stablecoin transactions
• In some cases, crypto debit card payments

This is comprehensive. It covers not just your obvious "cash out" moments but the full chain of on-platform activity. The wallet address data is particularly significant: HMRC can, in theory, correlate reported exchange data with on-chain activity to identify unreported holdings.

The Timeline: When Does HMRC Actually See Your 2026 Data?

Here is the detail most articles get wrong. CARF started on 1 January 2026 — but HMRC does not receive the data immediately.

The reporting cycle works like this:

• January–December 2026: Exchanges collect and record all user data and transactions
• By 31 May 2027: Exchanges submit the full 2026 dataset to HMRC
• From 2027 onwards: HMRC begins automatic international data exchange with partner jurisdictions

So the first real crunch point for UK users is the 2026–27 tax self-assessment, due 31 January 2027. By that date, you need to have reported your 2026 crypto gains — because by May 2027, HMRC will have independent corroborating data from your exchange. If your self-assessment does not match what the exchange reported, that is a problem.

The message is simple: you have time to get your records in order, but not much.

UK Capital Gains Tax on Crypto: 2026 Rates

HMRC treats cryptocurrency as a capital asset, not currency. That means disposing of crypto — selling it, swapping it for another token, spending it, or gifting it (outside of marriage) — is a taxable event.

For the 2025/26 and 2026/27 tax years:

Your CGT situation	Rate
Annual allowance (all gains below this: tax-free)	£3,000
Basic rate taxpayer (total income under £50,270)	18%
Higher/additional rate taxpayer (income over £50,270)	24%

Note the allowance: at just £3,000, it catches many more people than in previous years (it was £12,300 as recently as 2022/23). Even modest profits from a single bull-market trade can now exceed the threshold and create a reportable obligation.

Income tax applies separately to staking rewards, DeFi yields, and crypto received as payment for work or services. These are taxed at your marginal income rate, not at CGT rates.

For a complete breakdown of cost basis rules, Section 104 pooling, and how to calculate gains for HMRC self-assessment, see our dedicated UK Crypto Capital Gains Tax guide.

Which Exchanges Give UK Users the Best Tax Tools?

This is the question that almost nobody in the search results answers directly — so let us answer it.

Coinbase — Best Built-In Tax Centre

Coinbase remains the gold standard for UK tax reporting infrastructure. Users can generate downloadable transaction reports directly from the platform in CSV format, which is accepted by every major UK tax software. Coinbase also supports direct API integration with Recap and Koinly, two of the most widely used HMRC-compliant tools. For the average UK retail investor who uses one exchange and wants a frictionless tax workflow, Coinbase is hard to beat.

Key features: Full CSV export, API links to Koinly and Recap, clear transaction history UI, dedicated Tax Centre.

Kraken — Best for Active Traders

Kraken was one of the first major exchanges to publish explicit CARF FAQ documentation for users, signalling that it has seriously invested in compliance infrastructure. Its partnership with Koinly offers UK users a discount on tax plans, and the API integration is robust enough to handle high-frequency trading histories that would defeat manual tracking. Kraken's transparent Proof-of-Reserves and its track record on regulatory cooperation give it credibility here.

Key features: CARF documentation published, Koinly partnership with user discount, full API/CSV export.

Binance UK — Caveats Apply

Binance's UK situation requires a clear-eyed note: new user registrations have been paused since October 2023, and retail derivatives trading is suspended following FCA guidance that applies to all UK exchanges — not a Binance-specific sanction. Existing users can still trade spot, and Binance does offer transaction history exports compatible with Koinly and Recap.

However, given the registration freeze and the limitations on new UK accounts, Binance is not the recommended first choice for UK users starting fresh in 2026 — particularly with CARF compliance requiring stable, verifiable records. See our full UK exchange comparison for FCA-registered alternatives.

Key features: Existing users: full CSV export, third-party integration. New users: registration currently paused.

Best Tax Software for UK Crypto Users in 2026

Whichever exchange you use, standalone tax software remains essential for users with activity across multiple platforms or DeFi protocols.

Koinly — The most widely used by UK investors. Generates HMRC-compliant CGT summaries (SA108 format), integrates with 900+ exchanges, and supports DeFi and NFT transactions. Free plan covers basic imports; paid plans start at competitive rates.

Recap — UK-built, privacy-first, trusted by 50,000+ investors. Integrates with 350+ exchanges including Coinbase and Binance. Generates HMRC-ready reports for self-assessment. Strong customer support specifically focused on UK tax rules.

Blockpit — European competitor with strong HMRC rule implementation. Good for users with cross-EU exposure who will eventually need to comply with DAC8 (the EU equivalent of CARF).

What To Do Now: A Practical Checklist

The Bottom Line

CARF does not add a new tax — it adds new visibility. HMRC now has a structured data feed from every regulated UK exchange, covering your identity, your trades, and your wallets. The first full dataset arrives at HMRC by May 2027.

The good news: for users who already report honestly, CARF just means HMRC can verify what you declared. The exchanges with the best tax tools — Coinbase and Kraken leading the pack — make that verification painless. The bad news: for anyone who has been relying on opacity, 2026 is the last year that strategy was even theoretically viable.

Get your records straight. The data is already being collected.