CryptoTax UK · Guide
HMRC's Real Time Capital Gains Tax service: report crypto now, not in January
Most crypto investors wait until the January Self Assessment deadline to report their gains — but there is another option. HMRC's Real Time Capital Gains Tax service lets you report and pay your crypto CGT in-year, as soon as you make a disposal. It can simplify your tax affairs and avoid a large payment shock in January. Educational only — not tax advice.
Calculate my gains before reporting →What is the Real Time CGT service?
The Real Time CGT service is an HMRC online service that allows you to report capital gains and pay the tax due immediately after a disposal — without waiting for the end of the tax year. For crypto, this means you can report a disposal in June and pay the tax in July, rather than waiting until 31 January the following year.
Who can use it?
You can use the Real Time CGT service if you are a UK resident individual who has made a capital gain, you do not need to complete a full Self Assessment return for other reasons, and your total gains in the year do not exceed £50,000 (above this, you must use Self Assessment). If you already file Self Assessment for other income, include crypto gains there rather than using the real-time service.
How to use the Real Time CGT service
Access the service through your HMRC online account (Government Gateway). You report the disposal details — asset type, acquisition date and cost, disposal date and proceeds, and any allowable costs. HMRC calculates the tax due after applying your CGT allowance and any losses. You can pay immediately by bank transfer or debit card.
Advantages over waiting for Self Assessment
Using the real-time service has several benefits: it spreads your tax payments across the year rather than creating a single large January bill, it confirms your liability immediately so you know exactly where you stand, and it can simplify your January Self Assessment (you reference the payments already made). For investors who make significant mid-year disposals, it also improves cash flow planning.
Important: estimate carefully before paying
The Real Time CGT service requires you to estimate your gains accurately. If you over-report and overpay, you can claim a refund — but this takes time. If you under-report, interest accrues on the underpayment. Importantly, the £3,000 allowance applies to total annual gains — not each individual transaction. Using a complete calculation of all your crypto activity for the year before paying is strongly recommended.
Frequently asked questions
Does using the Real Time CGT service mean I don't need to file Self Assessment?
Only if you have no other reason to file Self Assessment. If you have other income, are self-employed, or have total gains over £50,000, you still need to file a full Self Assessment return. The real-time payments are credited against your Self Assessment liability.
Can I report losses through the Real Time CGT service?
The Real Time CGT service is primarily for reporting gains and paying tax. Losses should be reported through Self Assessment. However, you can take account of known losses when estimating your net gain for the real-time payment.
What if my total gains for the year end up being lower than I reported in real time?
If you made further disposals at a loss later in the year, your final annual gain will be lower. You can reclaim any overpayment through your Self Assessment return, which will show the real-time payments already made and calculate any refund due.
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Calculate my gains before reporting →Educational guidance only. CryptoTax UK is not a regulated tax adviser and the information above does not constitute tax, legal or financial advice. Always confirm your specific position with HMRC or a qualified accountant before filing.