Does Your Crypto Exchange Report You to the Tax Office? CARF and DAC8 Explained

Overview

For most of crypto's history, tax authorities had to go looking. They could request data from a specific exchange, follow information from another country, or notice money arriving in a bank account — but nothing arrived on its own.

That ended on 1 January 2026. Two frameworks came into force on the same date: the Cryptoasset Reporting Framework in the UK and elsewhere, and DAC8 across the European Union. Both require crypto platforms to collect standardised information about their users and report it annually, without anyone having to ask.

This is the same machinery that already exists for bank accounts under the Common Reporting Standard, extended to cryptoassets. This article covers what is collected, when it moves, and what it means in practice.

What CARF Is

The Cryptoasset Reporting Framework is an OECD standard. It requires reporting cryptoasset service providers — exchanges, brokers, and some other intermediaries — to carry out due diligence on their users and report transaction information to their local tax authority each year.

That authority then exchanges the information with the tax authority of the country where the user is resident.

The UK implemented it through the Reporting Cryptoasset Service Providers (Due Diligence and Reporting Requirements) Regulations 2025, with roughly fifty providers in scope initially.

DAC8 is the European Union's implementation of the same standard, delivered as an amendment to the directive on administrative cooperation. The underlying rules are aligned deliberately, so a platform operating in both places is not reporting two different things.

The Dates

When	What happens
1 January 2026	Rules take effect in the UK and across the EU; providers begin collecting and recording
31 December 2026	End of the first reportable period
1 January – 31 May 2027	UK providers submit their first reports to HMRC, covering calendar year 2026
By 30 September 2027	First EU reporting and exchanges under DAC8, covering 2026
During 2027	First international exchanges of CARF data between jurisdictions

The important point is that the collection is already happening. The reports arrive in 2027, but they describe what you did in 2026 — which is now.

The UK Went Further Than Required

This detail is regularly missed, and it matters.

The international framework is fundamentally about cross-border information: a platform reports on customers resident elsewhere, so that data can be sent to their home authority. Left there, it would not require a UK platform to report on a UK-resident customer to HMRC.

The UK extended the rules to cover domestic reporting as well. UK providers report on UK-resident customers directly to HMRC.

So the common assumption — that this is a problem for people using offshore exchanges and irrelevant if you use a UK platform — has it backwards. Using a UK-regulated exchange as a UK resident puts you squarely inside the domestic reporting rules.

Organise your transaction history

What Gets Collected About You

If you hold an account with a platform in scope, you will have been asked to confirm certain details, and the list is standardised:

full name;
date of birth;
address and country of residence;
tax identification number — a National Insurance number or Unique Taxpayer Reference for UK residents.

This is not optional, and it carries a specific consequence. Giving inaccurate details, or not giving them at all, can attract a penalty of up to £300. Penalties may be higher where a non-UK provider is involved.

If you have been ignoring emails from an exchange asking you to confirm your tax residence, that is what they are for.

Alongside the identity data, platforms report transaction information — exchanges between cryptoassets and fiat currency, exchanges between one cryptoasset and another, and transfers. Crypto-to-crypto activity being in scope is worth registering, since that is exactly the activity people most often assume is invisible.

What This Does and Does Not Mean

Some measured expectations are useful here.

It does not mean HMRC now knows your tax position. A platform reports transactions it can see. It does not know your cost basis, what you did before you arrived, what happened in your self-custody wallet, or which transfers were between your own accounts. The reported data is not a tax calculation.

It does mean discrepancies become visible. If reports show substantial disposal activity and there is no corresponding entry on a tax return, that gap is now easy to notice at scale, and it is exactly the kind of comparison automated systems are good at.

It does not cover everything. Decentralised exchanges, peer-to-peer trades and self-custody wallets are not intermediaries reporting on you. But assets generally enter and leave that world through platforms that are.

It does change the disclosure calculation. HMRC penalties depend heavily on whether a disclosure was unprompted. Once an authority holds data indicating undeclared gains, coming forward afterwards is much harder to characterise as voluntary — and the penalty difference between those two positions is substantial. The penalty bands are set out here.

The Records Problem This Creates

There is an asymmetry worth planning around.

Your exchange will report a set of transactions to a tax authority. You will separately report a tax position based on your own records. If those two accounts of the same year disagree, you want the difference to be explainable — a transfer to your own wallet that looks like a disposal from the platform's side, a deposit from a wallet that is really your own historic purchase.

That is much easier when your records are complete and contemporaneous than when they are reconstructed under time pressure. A transfer to a self-custody wallet is not a disposal, but you need the other side imported to demonstrate it. How wallet transfers are treated covers the point.

The other reason to sort this out now is more mundane: platforms disappear. An exchange that closes, exits your market, or restricts your account takes its export function with it. Data you can download today may not be downloadable later.

Connect your exchanges

Beyond the UK and EU

CARF is an OECD standard with a broad group of committed jurisdictions, and implementation dates vary. Some began alongside the UK and EU in 2026; others follow in 2027 and 2028.

For anyone with accounts in more than one country, the practical implication is that "my exchange is somewhere else" is a shrinking argument rather than a strategy. The framework exists specifically so that residence, not platform location, determines who receives the data.

Deadlines and filing requirements still differ by country. Crypto tax deadlines across Europe covers who files when.

What to Do Now

Nothing about these frameworks changes what tax you owe. They change who knows about it and when.

The sensible response is unexciting:

Respond to tax residence requests from your exchanges, accurately — there is a £300 penalty attached to not doing so.
Assemble your history for 2026 now, while every platform you have used is still accessible.
Include self-custody wallets, so transfers between your own accounts can be shown to be exactly that.
Deal with earlier years if they were never reported, before a report makes the disclosure prompted rather than voluntary.

Conclusion

The question in the title now has a straightforward answer: yes, if you use a centralised platform in the UK or EU, and the first reports covering 2026 are due in 2027.

This is not a crackdown so much as crypto being brought into the reporting machinery that has covered bank accounts for years. The compliant path is unchanged — keep complete records, report what is reportable, claim what you are entitled to. What has changed is that the alternative now has a date attached to it.

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Official Resources

This article provides general information and is not tax advice. Implementation dates vary by jurisdiction; check the rules that apply where you are resident.