Process summary
Receiving tokens from a Bitcoin fork or an airdrop is usually taxable in the UK. If tokens were given for services, treat them as income on receipt. If tokens were truly free with no expectation, tax usually applies on disposal as a capital gain.
Follow these six steps now.
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Decide the tax character quickly: income if linked to services; capital if genuinely free.
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Capture evidence at receipt: save the TXID, wallet or exchange screenshots and the GBP price.
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Use the correct valuation time. For income, use GBP market value when tokens are credited or when first tradable. Record the earlier of those two times and the source.
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For forks, allocate original cost under Section 104 pooling. Use market values at the first moment both chains have reliable GBP prices.
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Report on Self Assessment: income goes under "Other taxable income" or employment/self‑employment pages. Gains go on SA108 when disposed.
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Keep evidence for six years. Never share private keys with claim portals.
Take one clear step now. Capture time and GBP price.
Bitcoin forks & airdrops UK — quick take
Direct rule: Airdrops given for services or payment are taxable as income on receipt. Airdrops with no expectation are usually capital and taxed on disposal. Forks create a new asset that needs a split of original cost. Use market values at first tradability to allocate the cost. HM Revenue & Customs guidance has been updated through 2026 and applies the facts and circumstances test.
Actionable: Capture a timestamped GBP price within 24 hours of credit. Export CSV from the wallet or exchange. Save a screenshot showing the trading pair and time. Label files with the snapshot date. Keep everything for at least 6 years.
Practical 2026 checklist for machine‑readable records follows. HMRC examiners now expect clear, dated CSVs. The minimum fields are UTC timestamp, TXID or block, receiving wallet, asset symbol, units credited, GBP value, conversion source and custody flag.
Produce a one‑page cover note naming the valuation time and conversion chain. Attach CSVs and screenshots that match those columns.
Step 1: decide tax character
Decide if the receipt is income or capital. This choice changes timing and allowances.
Ask three questions: was anything given in return; was the receipt linked to work, marketing or services; was there an expectation to receive tokens for an action? If any answer is yes, treat it as income.
Examples help. A referral bonus likely counts as income. A random promotional drop with no strings is likely capital.
Write one short note explaining the decision. Attach project announcements or invoices to the note. That note helps if HMRC queries the treatment.
A clear note avoids long disputes.
Step 2: record and value at receipt, exact fields to capture
Capture evidence when tokens first appear in the wallet or exchange. The correct GBP value and timestamp are the core facts HMRC will ask for. Missing these makes later valuation guesswork.
Minimum evidence list: save each item as a separate file.
- UTC timestamp of receipt or snapshot
- Transaction ID (TXID) or block hash
- Receiving wallet address
- Exchange credit screenshot showing asset, units and time
- Market price source for GBP value (exchange, CoinDesk, Bank of England)
- Project announcement with snapshot conditions and date
- CSV export of the wallet or exchange ledger
Name files clearly, for example "2026-06-05_BCH_credit_binance.png". Keep PDFs and CSVs.
"The tax consequences will depend on the particular facts and the role of the tokens." HM Revenue & Customs, Cryptoassets Manual
Warning: Never follow a claim portal that asks for private keys. If a claim needs a private key, treat it as a scam. Do not sign any transaction that transfers funds away from the holder.
Valuation rules and conversion sources
Use the market GBP value when the token became capable of being disposed of. If credited on an exchange, use the exchange quote at that timestamp. If no GBP pair exists, convert via a major pair then use Bank of England or CoinDesk to convert USD to GBP. Record the conversion source and timestamp.
If the first tradable market is illiquid, take the midpoint between best bid and ask at that timestamp. Keep an orderbook screenshot. Explain the choice in one line in the evidence pack.
Snapshot
Record block height and time
→
Credit
Exchange or wallet credit and TXID
→
Value
GBP price at tradable moment
→
Allocate
Split original cost for forks
→
Dispose
[Report](https://mindyourownbusiness.uk/airdrops-hard-forks-tax-uk/) proceeds and gain
Collect these items now.
Step 3: allocate cost basis for bitcoin forks
When a hard fork creates a new coin, split the original acquisition cost. HMRC expects an economic allocation based on market values when both assets first trade. That allocation becomes each asset's cost basis.
Practical rule clarified. Use the first timestamp where both chains have reliable, observable GBP prices. Total market value equals GBP value of the old chain plus GBP value of the new chain at that timestamp. Allocate the original cost proportionally.
If one chain is not tradeable, document a transparent proxy. For example, convert via a liquid USD pair and use a reputable USD→GBP rate. Capture orderbook mid‑price and show the conversion math in the evidence pack.
Multiply the original acquisition cost by each chain's share to get allocated costs. Keep the math clear in a spreadsheet.
Worked example with numbers from a 2016 purchase.
- 1 BTC bought for £2,000.
- At first tradable moment: BTC = £40,000; new coin (BCH) = £600.
- Total market value = £40,600.
- BTC share = 40,000 / 40,600 = 0.9852. Allocated cost to BTC = £1,970.
- BCH share = 600 / 40,600 = 0.0148. Allocated cost to BCH = £30.
If BCH is later sold for £800, the gain = £800 minus £30. Report that gain on SA108 for 2026/27.
Multiple purchases need Section 104 pooling. Add all historical costs together. Then allocate the pooled cost proportionally using the market value split at fork time.
Same‑day and 30‑day matching rules still apply on disposals where relevant. Record exchange timestamps to show which rule applies.
Step 4: report on self assessment, exact entries and sample text
If the receipt is income, include the GBP value at receipt under "Other taxable income". If linked to work, use the self‑employment or employment pages. Income taxed at receipt may attract Class 2 or Class 4 National Insurance where self‑employed.
If the receipt was capital, report gains on SA108 when a disposal occurs. Provide disposal date, asset description, proceeds in GBP, allowable cost and gain or loss.
| Date of disposal |
Asset |
Proceeds (GBP) |
Allowable costs (GBP) |
Gain (GBP) |
| 15 June 2026 |
BCH (forked from BTC) |
£800.00 |
£30.00 |
£770.00 |
Sample text for the SA100 "Additional information" box follows. Paste it directly if it matches facts.
"5 June 2026. Received BCH at hard fork snapshot. Market values at first tradability:
- BTC £40,000
- BCH £600. Original BTC cost £2,000 allocated proportionally. TXID: [hash]. Evidence files: 2026-06-05_BCH_allocation.xlsx
- 2026-06-05_binance_credit.png"
If the receipt was income, use this short factual line under 'Other taxable income'.
"5 June 2026. Received 100 XYZ airdrop as reward for marketing. Market value at receipt £500. TXID: [hash]. Evidence attached."
Keep uploads short and labelled. HMRC may ask for originals. Do not send private keys.
HMRC hint: If the return may trigger a query, include a one‑page cover note summarising the calculation, the chosen valuation time, conversion source and a list of attached evidence filenames.
Prepare the pack now.
Provide a clear spreadsheet layout that shows the calculation path HMRC expects. Use separate tabs for transactions, fork allocation, disposals and an evidence index.
Transactions tab columns: Date (UTC), TXID or Block, Asset, Units, GBP value at timestamp, Source, Custody, Reason and Notes.
Fork allocation tab columns and formula example: Original asset units, Original acquisition cost (GBP), BTC market value at fork timestamp (GBP), New coin market value at fork timestamp (GBP), Allocated cost to new coin = (NewCoinValue / (BTCValue + NewCoinValue)) * OriginalAcquisitionCost.
Disposals & gains tab columns: Disposal date, Asset, Units sold, Proceeds (GBP), Allocated acquisition cost (GBP), Gain/Loss = Proceeds - AllocatedAcquisitionCost, Pool rule applied.
Evidence index tab columns: Filename, Short description, Capture date, Hash or checksum, Storage location.
Exact Excel example for allocation cell: = (C2 / (B2 + C2)) * D2 where B2 = BTCValue, C2 = NewCoinValue, D2 = OriginalAcquisitionCost.
Use the schema now. It saves time during any HMRC query.
Real UK case study: claiming airdrop income
A London freelance developer received an airdrop after a bug bounty. The project credited 200 tokens and a BTC pair quoted a GBP value of £1,200 when credited.
The developer treated the receipt as trading income. The figure went under 'Other taxable income' for the 2022/23 Self Assessment. Evidence included project emails, an invoice, the exchange credit screenshot with timestamp and TXID, and the CSV ledger.
HMRC queried the return; the taxpayer supplied the evidence pack. HMRC accepted the tax treatment and closed the case.
Lesson: contemporaneous evidence and a short reasoning note avoided a long dispute. Getting advice early would have cut stress.
Step‑by‑step numeric example for an airdrop.
- Received 200 tokens on 15 June 2026 at £2.50 each. Total value = £500.
- If taxable as miscellaneous income, declare £500 in 2026/27 Self Assessment under 'Other taxable income'.
- For a basic‑rate taxpayer at 20% the tax is £100 on that income.
- If Class 4 NIC at about 9% applies, add roughly £45 in NICs. Total immediate cost about £145.
Keep the wording ready to paste into SA100.
Errors that ruin the result, common mistakes
Missing a timestamped GBP value at receipt is the most damaging error. Without it, any later valuation looks like a guess.
Assuming every airdrop is a CGT event can also ruin results. Some airdrops are income. The wrong choice changes tax years and NICs.
Sharing private keys or using unverified claim portals risks theft. Never sign transfers to unfamiliar contracts without review.
Relying on arbitrary exchange rates without documenting the source is risky. HMRC asks for the conversion source. Use Bank of England, CoinDesk or a reputable exchange and save a screenshot.
Failing to allocate forked cost correctly will cause wrong gain calculations later.
When this method does not apply / alternatives
This guidance does not apply if the taxpayer was non‑UK resident at receipt. Residency changes tax position materially.
It also does not apply where tokens were part of an employment package already taxed under PAYE. In that case, follow employment reporting rules.
If the assets are held by a company, Corporation Tax rules apply. Trading businesses may need to treat receipts under trading accounts. Professional advice is needed in those cases.
If a tax agent already reported and allocated the basis, follow the agent's record. Reallocating without agreement can trigger inconsistencies.
Consider professional help for complex cases.
Avoiding mistakes, scams and HMRC pitfalls, security checklist
Never share private keys. No valid claim needs the private key for a read‑only claim.
Verify official project channels and domain names before clicking claim links. Prefer exchange credit when possible. Use the exchange's process rather than manual contracts.
If the first credit is on an exchange, capture the exchange page and ledger CSV. If an airdrop needs signing a message, check the purpose and consequences before signing.
If theft is suspected, keep evidence, contact the exchange and consider reporting to the police.
Watch this scam pattern: a site asks for a wallet signature then requests a transfer. That is a red flag. Another pattern is a cloned exchange login page. Use two‑factor authentication and withdraw to cold storage through verified steps.
FAQ — common questions
Are airdrops taxable in the UK?
They can be. If tokens are given for services or work, they are income when received. If truly free with no expectation, they are usually capital and taxed on disposal. Record the reason and attach evidence. If unsure, treat as income and seek advice.
Can HMRC see your bitcoin?
HMRC cannot read private keys. HMRC can request data from exchanges and use blockchain analysis firms. Exchanges like Coinbase, Binance and Kraken have shared data with HMRC in the past. Good records reduce audit risk.
What is the 51% rule in bitcoin?
The 51% concept means a miner or group controls most hashing power. That can damage confidence in a fork. For tax, it affects valuation and whether a new chain is viable. If an attack happens, document the event and note any market impact.
What does Martin Lewis say about bitcoin?
Martin Lewis warns consumers about crypto risk and scams. He urges caution and avoiding bets with essential money. For tax, his point stands: keep records and avoid relying on memory.
How to value tokens credited by an exchange without a GBP pair?
Convert via a major quoted pair, typically USD or BTC first. Then use Bank of England or CoinDesk to convert to GBP at the same timestamp. Save screenshots of both quotes and document steps in the evidence index.
What if the GBP value at receipt was not captured, how to reconstruct it?
Use the nearest credible market price when the asset first became tradable. Capture orderbook screenshots and the nearest trade price. Add a short note that explains why that time was chosen. Show the reconstruction in the spreadsheet.
Small promotional airdrops may still be reportable. If no service or expectation, they are likely capital and taxable on disposal. If you later sell them, report the sale. Keep records even if the immediate tax seems nil.
Final action plan
- Capture all outstanding evidence now. Export CSVs and screenshots with timestamps and hash the files.
- Populate the spreadsheet with transactions and run fork allocations. Use the allocation formula in Step 5.
- Decide if receipts are income or capital and write one short note for each event.
- Prepare Self Assessment entries or contact an agent if figures are complex.
- Secure assets and avoid any claim process that needs private keys.
This playbook is current to April 2026 and follows HMRC guidance in the Cryptoassets Manual and the UK Cryptoasset Taskforce view on taxing crypto. Keep records for at least six years. For complex forks or corporate holdings, consult a specialist adviser.
