Voluntary Disclosure Letter Builder — HMRC

Follow the four steps below. Use Koinly to compile & calculate, then draft your letter here, and finally submit via HMRC’s Digital Disclosure Service (DDS).

Get your Koinly report (Opens in a new tab — affiliate link)

Compile your crypto records with Koinly

Connect all exchanges, wallets and blockchains in Koinly to build a complete transaction history.

Auto-completes when you add a Koinly reference below

Calculate what’s owed

Use Koinly’s Capital Gains & Income reports to estimate tax due per year. Export PDF/CSV; you’ll reference them in your letter.

Auto-completes when you enter estimated amounts

Draft your disclosure letter

Fill the form and generate a clear letter suitable for HMRC’s DDS.

Auto-completes when you generate the letter

Submit via HMRC Digital Disclosure Service (DDS)

Notify HMRC of your disclosure, then upload your letter and Koinly reports.

Open DDS I’ve submitted via DDS

Note: This tool does not send data to HMRC. It drafts your letter and helps you organise your evidence.

Your details

Full name Address (your postal address)

National Insurance No. (optional)

Date of birth

HMRC recipient

HMRC office / department HMRC postal address

Confirm the correct HMRC postal address for voluntary disclosures (it can vary by case/region).

Disclosure summary

Nature of undeclared activity Tax years affected (comma-separated) Period when issue occurred (approx) Short factual summary of what happened Actions taken to date (e.g. Koinly export, reconciliation) Koinly / tax reporting link or ref

Amounts & calculations

Estimated total value involved (GBP) Estimated tax shortfall (GBP, if known) Interest / penalties paid (if any)

Mitigation / intention

Reason / cause (brief) Proposed remedy / offer to HMRC

Declaration & signature

Declaration line (default included) Signed (typed name acceptable) Date (signature date)

Export: After generating, use the buttons on the right to copy, print, or download PDF. Check HMRC address and get professional advice before sending.

Letter preview

Read-only — generate to update

(Generated letter will appear here)

Note: Browser Print (Cmd/Ctrl+P) and “Download PDF” both produce a printable letter.

Tool notes

Use Koinly to generate exports; include the exact report reference in your letter.
Attach CSVs/exports or offer to provide them on request.
This is a drafting aid, not tax or legal advice.