HMRC believes you may owe tax on crypto
HMRC receives data from UK exchanges and overseas reporting agreements. A letter usually means your name appears in that data and they expect you to review your position.
HMRC crypto correspondence
Received an HMRC crypto letter? Here's how to respond properly.
UK crypto tax specialists. We review your letter, reconcile your wallets and exchanges, and prepare an accurate response or disclosure — so you act on facts, not guesswork.
HMRC-ready figures
Voluntary disclosure or amended return
Fixed fee agreed up front
Most HMRC nudge letters set a 30–60 day deadline. Acting early — even just to acknowledge — keeps you in the lowest penalty bands.
What the letter means
Read this before you reply
How you handle the first reply tends to set the tone for everything that follows. A clear, accurate response usually keeps things to a short correction. A vague or rushed one is what turns a letter into a full enquiry.
It's a prompt to act, not (yet) a formal investigation
Nudge / one-to-many letters give you a window to disclose or amend voluntarily. Acting promptly reduces penalties materially compared with waiting for HMRC to open an enquiry.
Doing nothing is the worst outcome
Ignoring the letter typically escalates to a formal enquiry, higher penalties (up to 100% of tax owed), and interest accruing from the original due date.
Accurate numbers matter more than speed
A response based on guesswork or a rushed export usually creates more problems. The right path is a defensible calculation across every wallet and exchange you used.
How we help
From letter to clean response in three steps
Step 1
Short call
We read your letter, confirm what HMRC is asking for, and agree the years and scope.
Step 2
Reconcile your activity
We pull together exchange exports and on-chain history, run the capital gains and income calculations to HMRC rules, and flag any gaps.
Step 3
Respond properly
We prepare the figures and supporting workings for a Digital Disclosure Service submission, amended return, or written response — whichever fits.
Who you'll be working with
UK-qualified, crypto-specialist, accountable.
BlockBooks is led by Tim Whitehouse, who started his career in audit at EY before working in their acquisition due diligence team and then building a cloud accounting practice. HMRC correspondence work is handled directly, not passed to a back office.
UK Self Assessment specialistFull audit trail of workingsFixed fee before work begins
FAQ
What people ask when the letter arrives
How long do I have to respond?
Most HMRC nudge letters give 30 to 60 days to respond. Even if the window is tight, replying with a clear plan and timeline is far better than silence.
Will I get fined?
Penalties depend on whether HMRC sees the disclosure as prompted or unprompted, and whether the underpayment was careless or deliberate. A well-prepared voluntary disclosure usually attracts the lowest penalty range. We'll explain the bands that apply to your case before any submission.
What if I don't have all my records?
This is the normal starting position. Most exchanges allow you to re-download historical CSV exports, and on-chain wallet activity can usually be reconstructed from the public ledger. We do this routinely.
I only had DeFi or staking activity — does the letter still apply?
Yes. HMRC's data collection extends beyond plain exchange trading. DeFi, staking, lending, NFTs and bridging can all create taxable events that need reporting.
How much does this cost?
Fees depend on the number of wallets, exchanges and years in scope. Straightforward cases start around £250 per tax year. We confirm a fixed fee before any detailed work begins.