Have You Had a Letter From HMRC About Your Crypto? Here's What It Means

If you've invested in cryptocurrency and recently received a letter from HMRC asking you to check whether you've declared all your income and gains, you're not alone. HMRC has been sending these nudge letters to crypto investors across the UK in increasing numbers — and the pace of that activity is only going to increase.

This isn't scaremongering. It's a genuine shift in how HMRC is approaching crypto taxation, and if you've received one of these letters, understanding what it means and what to do next is important.

Why is HMRC targeting crypto investors?

For a long time, cryptocurrency existed in a bit of a grey area for many investors. The rules were unclear, reporting was inconsistent, and HMRC's ability to track crypto activity was limited. That's changed significantly.

There are around seven million UK adults now holding crypto assets, with total values running into the billions. HMRC has substantially improved its data gathering capabilities and now receives information directly from cryptocurrency exchanges and wallet providers, allowing it to identify individuals who may not have declared gains or income from their crypto activity.

On top of that, a new international framework called the Crypto-Asset Reporting Framework (CARF) — developed by the OECD — will from 2026 require crypto service providers to share detailed transaction data with HMRC as a matter of course. HMRC is effectively getting ahead of that curve now, using the data it already has to prompt investors to review and correct their tax affairs before the reporting net tightens further.

The nudge letters are the result of all of this coming together. If you've received one, it's because HMRC's data suggests your crypto activity may not have been fully declared.

Is crypto actually taxable in the UK?

Yes — and more transactions than people realise can trigger a tax liability.

HMRC doesn't treat cryptocurrency as currency. It treats it as a capital asset in most cases, which means disposing of it can give rise to Capital Gains Tax. A disposal isn't just selling crypto for pounds — it includes exchanging one cryptocurrency for another, spending crypto on goods or services, and gifting crypto to someone other than a spouse or civil partner.

If your crypto activity looks more like trading — frequent buying and selling, or earning crypto through mining, staking, or airdrops — HMRC may treat that income as subject to Income Tax and potentially National Insurance instead of, or in addition to, Capital Gains Tax.

Simply holding crypto without doing anything with it generally doesn't trigger a tax event. But the moment you do something with it, there's a reasonable chance a tax obligation arises.

What should you do if you've received a nudge letter?

The most important thing is not to ignore it. A nudge letter is HMRC giving you the opportunity to put things right voluntarily — and that's always a better position to be in than waiting for HMRC to open a formal investigation.

Here's a sensible approach to working through it.

Start by reading the letter carefully. It's asking you to check your position, not accusing you of wrongdoing. Responding doesn't mean you've admitted to anything — it's simply an opportunity to review whether everything is in order.

Next, gather your records. Go through your crypto activity across all exchanges and wallets and pull together details of every transaction — buys, sells, swaps, gifts, staking rewards, airdrops, and any crypto you've spent. For each transaction you'll need the date, the sterling value at the time, and whether it constituted a disposal.

From there, work out whether tax was owed in any of the relevant years. If you find something that wasn't declared and you're within the amendment window for your Self Assessment return, you may be able to correct it directly. If you're outside that window, or the position is more complex, a voluntary disclosure through HMRC's crypto disclosure facility is likely the right route.

Going forward, keep proper records of all your crypto transactions as you make them. Maintaining clear evidence of dates, sterling values, and transaction types will protect you if HMRC asks questions in future — and given the direction of travel, it's a question of when rather than if.

What if you've been underdeclaring for several years?

This is more common than people realise, particularly among investors who got into crypto in its earlier years when tax guidance was less clear and record keeping was patchy. If you think you may have underdeclared gains or income across multiple years, the voluntary disclosure route is almost always the better option compared to doing nothing.

HMRC generally takes a more favourable view of taxpayers who come forward proactively — penalties tend to be lower, the process is more controlled, and you avoid the risk of a more intrusive investigation further down the line. The window for acting voluntarily narrows as HMRC's data improves, so the sooner you address it, the more options you have.

How can we help?

Crypto taxation is genuinely complex — the rules around pooling, valuation, staking income, and the distinction between capital gains and trading income aren't always straightforward to apply, particularly when you're dealing with multiple years of transactions across different platforms.

At Alera Accounting & Advisory, we can help you work out exactly what your tax position is, calculate any liability accurately — making sure allowable costs and annual exemptions are properly applied — handle any communication or disclosure with HMRC on your behalf, and put a proper record-keeping process in place going forward.

If you've received a nudge letter, or you've had significant crypto activity and you're not sure whether it's been properly declared, get in touch with our team today for a confidential conversation.