Payments on Account for Crypto: Why July Ignores Your Gains

You filed your crypto taxes in January. Then a letter (or a login to your HMRC account) tells you another payment is due on 31 July. Or — just as confusing — your friend with a near-identical portfolio owes thousands in July and you owe nothing.

The mechanism behind this is payments on account: HMRC's system of advance instalments towards next year's tax bill. It is the most misunderstood part of Self Assessment for crypto investors, because it treats your two kinds of crypto money in opposite ways. Profits from selling or swapping tokens never enter payments on account, no matter how large. Income from staking, lending, and airdrops does.

That split — capital gains versus income — is decided transaction by transaction, by how each one is classified. Get the classification right and your July bill is predictable. Get it wrong and you are either funding HMRC months early or storing up backdated interest. And if you've received an HMRC nudge letter, reconciling that income-versus-gains split is part of the review it asks for. Here is how the system actually works.

What payments on account are — and the £1,000 trigger

Payments on account (section 59A, Taxes Management Act 1970) are two advance instalments towards the comingyear's tax bill, each equal to 50% of the income tax and Class 4 National Insurance you self-assessed for the year just filed. They are due on 31 January (alongside the balance for the year you are filing) and 31 July.

You are pulled into the regime when both of these are true for the year you just filed:

• The self-assessed part of your bill — tax HMRC could not collect at source — is £1,000 or more
• Less than 80% of your total tax for the year was collected at source (for most people, through PAYE on a salary)

The second condition matters for employed crypto investors. If your salary is large relative to your crypto income, PAYE may already cover more than 80% of your total liability, and no payments on account are due even when the crypto bill itself clears £1,000. It is worth checking the ratio before assuming July applies to you.

The rule crypto investors miss: capital gains never enter payments on account

Payments on account are computed on income tax and Class 4 National Insurance only. Capital Gains Tax is excluded entirely. However large your disposal gains — selling ETH, swapping tokens, removing liquidity — the CGT on them is paid once, as part of the balancing payment on 31 January after the tax year ends. It never generates a July instalment, and it never inflates next year's advance payments.

This is good news for most crypto investors, whose bills are dominated by disposal gains. A £50,000 trading year creates exactly one payment date. But it cuts the other way too: because CGT sits outside the instalment system, HMRC expects the wholeamount in one go. There is no spreading, and the £1,000 payments-on-account threshold is tested against the income-tax side of your bill alone — not the total.

So the question that decides your July is not "how much did I make from crypto?" It is "how much of what I made was income rather than capital gains?"

When crypto does create payments on account

HMRC treats most reward-shaped crypto receipts as miscellaneous income(Cryptoassets Manual CRYPTO61214 for DeFi returns), taxed at your marginal rate — 20%, 40%, or 45% — at the GBP value on the day each reward arrived. That includes:

• Staking rewards — ETH validator income, Lido, exchange staking programmes
• Lending and liquidity-mining rewards — CRV emissions, Aave incentives
• Airdrops received in return for something — most major ones
• Referral bonuses, learn-to-earn rewards, cashback paid in crypto

None of this carries National Insurance for an investor, but all of it lands on the income-tax side of your return (SA100 "Other income", not SA108). The first £1,000 can be covered by the trading and miscellaneous income allowance; above that, it is taxable income — and once the tax on it crosses the £1,000 threshold, it sets the size of two advance instalments for the following year.

Worked example — two investors, £11,000 each, opposite July bills

Investor B's instalments are not extra tax — they are credited against the 2026/27 bill when it is filed. But the cash-flow difference is real, it arrives without much warning, and it repeats every January and July for as long as the staking income continues.

Reducing payments on account — and the interest trap

Each instalment assumes this year's income will match last year's. Crypto income rarely cooperates: protocols cut emissions, you unstake, a one-off airdrop does not repeat. If you expect this year's income to be lower, you can claim to reduce your payments on account — online through your HMRC account, or on form SA303.

The trap is over-reducing. If you cut the instalments below what the final bill turns out to be, HMRC charges late-payment interest — Bank of England base rate plus 4 percentage points — on the shortfall, backdated to each instalment's original due date. A January claim that turns out 18 months optimistic accrues interest the entire time.

The honest answer is that you can only reduce confidently if you know what your income year-to-date actually is — every reward, valued in GBP on its receipt date. Guessing from a vague sense of "I staked less this year" is how people end up with interest charges.

How the income/gains split flows through your return

The split that drives all of this is made long before the payment deadlines — it is made when each transaction is classified:

• Disposals(sells, swaps, liquidity removals) → SA108, Capital Gains Tax, one balancing payment, never in payments on account
• Income(staking, lending rewards, qualifying airdrops) → SA100 "Other income", income tax, feeds the £1,000 trigger and next year's instalments

Misclassify income as a zero-cost disposal and you overpay CGT while understating the income that HMRC expects payments on account against. Misclassify a disposal as income and you inflate your July bills for a year. The classification is not a labelling nicety — it changes when you pay as well as how much. A UK crypto tax calculator that separates the two correctly is doing the payments-on-account groundwork for you, whether you noticed or not.

Key dates for 2026 and 2027

• 31 July 2026— second payment on account towards 2025/26, sized by your 2024/25 income-tax bill. If your income has genuinely fallen, a reduction claim before this date trims the instalment itself.
• 31 January 2027 — balancing payment for the 2025/26 tax year (including all of its CGT), plus the first 2026/27 instalment if your income-tax bill stayed over the threshold.
• Miss an instalment and late-payment interest runs from the due date. Miss the balancing payment and penalties stack on top from 30 days late.

How ChainTax helps with payments on account

1. Every transaction classified income or disposal. Staking rewards, gauge emissions, and airdrop claims are categorised as Income; sells, swaps, and liquidity exits as Disposal — per-protocol, with the reasoning shown for each one.
2. SA100 and SA108 totals kept separate.Your report splits DeFi income from capital gains, so the figure that drives the £1,000 trigger — and the size of each instalment — is readable at a glance rather than buried in a transaction list.
3. Income valued at receipt-date GBP. Each reward is priced on the day it arrived, which is exactly the number you need for a defensible SA303 reduction claim.
4. Salary-aware estimates.Add your salary in settings and the report estimates income tax at your actual marginal rate — the same arithmetic HMRC's instalments are based on.