First HMRC report due 31 May 2027 — the data obligation started 1 Jan 2026

Get CARF ready.

Every UK-connected crypto platform — exchange, broker, OTC desk, custodial wallet — has been accruing reporting obligations to HMRC since January 2026, with penalties charged per user. CARFdesk is the HMRC-first toolkit for getting compliant: free tools, practitioner guides, no signup walls.

£300

per user, where transactions continue without a valid self-certification

31 May 2027

first CARF report to HMRC, covering all of 2026

~50

jurisdictions exchanging CARF data with HMRC from 2027

Free tools

CARF XML validator

Drop a report file, get OECD-schema validation with readable errors — in your browser, never uploaded.

Coming next: TIN format validator.

Deadline reminders and guidance updates

One email when something changes — HMRC guidance, OECD schema updates, deadline milestones. No newsletter padding.