UK Crypto Tax Share Matching Rules explained
Same-day, 30-day rule and Section 104 pool logic for crypto disposals under HMRC practice.
CoinTaxReporting applies UK-style share matching in the expected order: same-day acquisitions first, then acquisitions within the next 30 days, then the Section 104 pool for the remaining quantity.
This gives you a transparent gain/loss calculation per disposal with full matching evidence, pooled basis updates, fee treatment, and an audit trail suitable for accountant review and HMRC documentation.
Häufig gestellte Fragen
What are UK share matching rules for crypto?
They are matching rules used to assign acquisition cost to each disposal, commonly using same-day, then 30-day matching, then the Section 104 pool.
What is the 30-day rule (bed and breakfast)?
Disposals can be matched to acquisitions made within the following 30 days before falling back to pooled holdings.
Why does this matter for tax?
Because matching order directly changes the gain or loss and therefore the taxable outcome.
What is the exact matching order used?
The expected order is: same-day acquisitions first, then acquisitions made in the following 30 days, then Section 104 pool for any remaining disposal quantity.
How are trading fees treated in calculations?
Fees are included as part of acquisition or disposal economics where relevant, so net proceeds and net cost basis remain consistent at disposal level.
Can I still use this if I trade across multiple exchanges and wallets?
Yes. Data from multiple exchanges and wallets can be consolidated first, then matching is applied on the unified transaction history.
What if my imports contain duplicates or missing transactions?
You should clean data quality first. Duplicate or missing events can distort pool balances and gains. CoinTaxReporting provides structured review and traceability to resolve this.
Does the report show how each disposal was matched?
Yes. Each disposal can be traced to matched lots and/or pool basis, making it easier to validate results with an accountant.
Is this intended as tax advice?
No. The page explains computational logic and documentation workflow. For personal tax advice, consult a qualified UK tax professional.
How UK Crypto Share Matching Works in Practice
For each disposal, the calculation follows a strict sequence. The same disposal can be split across multiple matching buckets: same-day buys, then the next 30 days, then the Section 104 pool. This order directly affects taxable gains.
- Same-day rule: match disposals against acquisitions on the same day first.
- 30-day rule: match any remaining disposal amount against acquisitions in the following 30 days.
- Section 104 pool: apply pooled average basis for the residual quantity.
Why Many Reports Go Wrong
- Unmerged histories across exchanges and wallets.
- Duplicate imports that inflate holdings or basis.
- Missing withdrawals/deposits that break continuity.
- Incorrect fee handling that shifts gains/losses.
- No disposal-level evidence to verify matching outcomes.
What a Good UK-Crypto Report Should Include
- Disposal-by-disposal proceeds and matched cost basis.
- Visibility into same-day and 30-day matches.
- Section 104 pool opening/closing movements.
- Consistent fee treatment and net result logic.
- Exportable documentation for accountant/HMRC workflow.
Implementation Notes for Active Traders
If you trade frequently, matching quality depends on data quality first. Consolidate all sources, normalize timestamps, classify transfers correctly, then run matching. This avoids artificial gains from broken history or partial imports.