Corporation Tax deadlines: when your company's bill is due

Most limited companies must pay Corporation Tax nine months and one day after their accounting period ends, if their taxable profits are up to £1.5m. The Company Tax Return comes later: it's due 12 months after the period ends. Larger companies pay in quarterly instalments. Find your dates in the table below.

You pay before you file. For an accounting period ending 31 March 2026, the bill is due by 1 January 2027, three months before the return deadline of 31 March 2027.

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When is Corporation Tax due?

If your company's taxable profits are up to £1.5m, you pay Corporation Tax in one payment, nine months and one day after your accounting period ends. Above £1.5m, you pay in quarterly instalments instead.

Your accounting period is normally the 12 months your annual accounts cover. You can check its exact dates in your company's HMRC online account. If your company has nothing to pay, you still need to tell HMRC by the same deadline, using the 'nil to pay' form.

The deadline is the date the money reaches HMRC, not the date you send it. If it falls on a weekend or bank holiday, make sure the payment arrives on the last working day before, unless you pay by Faster Payments. Allow for how long your payment method takes:

• Faster Payments usually arrive the same or next day, weekends and bank holidays included.
• Bacs takes three working days.
• A Direct Debit takes five working days the first time you set one up, then three.

Each accounting period has its own 17-character payment reference, so check it every time. Our guide to Corporation Tax payments covers the ways to pay and how long each takes to clear.

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Corporation Tax payment dates by year-end

To find your payment date, take the last day of your accounting period, add nine months, then add one day. The table gives the dates for common 12-month periods ending in 2026. Make sure to still file your Company Tax Return within your 12-month window.

These dates apply if your taxable profits are up to £1.5m and you don't pay in instalments. They're worked out from gov.uk's rules, so confirm your own dates in your HMRC online account.

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When is the Company Tax Return due?

Your Company Tax Return is due 12 months after the end of the accounting period it covers, three months after the payment deadline. So most companies pay first and file second.

It's when you prepare the return that you work out the final figure, so it helps to have your numbers ready before the payment date. The filing deadline has its own rules and penalties, which we cover in our guide to the limited company tax return deadline.

Your annual accounts for Companies House are a separate job, due nine months after your financial year ends.

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Quarterly instalments for large companies

Companies with taxable profits above £1.5m usually pay Corporation Tax in four quarterly instalments, two of them before the accounting period ends. Above £20m, the instalments start even earlier.

For a 12-month accounting period, the first instalment is due six months and 13 days after the period starts. The next two follow at three-month intervals, and the last is due three months and 14 days after the period ends. Here's gov.uk's example for an accounting period from 1 January 2026 to 31 December 2026:

Companies with profits above £20m ('very large' companies) pay on the 14th day of months three, six, nine and 12 of the accounting period.

You don't have to pay by instalments if either of these applies:

• Your company's total Corporation Tax for the period is under £10,000.
• Your profits are no more than £10m and your company wasn't large (or didn't exist) in the previous 12 months, so your first period over the threshold is paid in one go.

That first-year grace doesn't apply to very large companies. Associated companies also change the picture: the thresholds are divided between them. In gov.uk's example, a company with five associated companies has a threshold of £1.5m divided by six, which is £250,000.

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Your first year: two accounting periods, two payment dates

An accounting period for Corporation Tax can't be longer than 12 months. If your first accounts cover more, you file two returns and have two payment deadlines.

gov.uk's example is a company set up and trading from 11 May 2024, with first accounts running to 31 May 2025:

After the first year, you'll normally file one return a year, covering the same financial year as your accounts.

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What happens if you pay Corporation Tax late?

If you pay late, HMRC charges interest on the unpaid tax for every day from the day after the deadline until you pay. The rate is the Bank of England base rate plus 4%, which is 7.75% from 9 January 2026.

The plus 4% applies from 6 April 2025. Before that, it was base rate plus 2.5%. HMRC doesn't charge interest on interest. The rate moves with Bank Rate, which the Bank of England held at 3.75% at its latest decision. Check HMRC's current rates before you work out a figure.

Worked example (illustrative): a £20,000 bill paid 30 days late at 7.75% costs about £20,000 × 7.75% × 30 ÷ 365 = £127.40 in interest. HMRC lets you deduct late payment interest as an expense for Corporation Tax.

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What happens if you file the return late?

HMRC charges late filing penalties even if there's no tax to pay. For returns with a filing date on or after 1 April 2026, it's £200 the day after the deadline and another £200 at three months. Tax-based penalties follow at six and 12 months.

If your return is late three times in a row, the £200 penalties rise to £1,000 each. You can appeal if you have a reasonable excuse, but you need to file the return first.

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If you can't pay on time: Time to Pay or borrowing

Talk to HMRC before the deadline passes. If the shortfall will take months to clear, an HMRC Time to Pay plan may fit. If the cash is coming in soon, a business loan can help you pay the bill on time, but it costs interest and, at iwoca, needs a director's personal guarantee.

Time to Pay lets your company spread a bill in monthly instalments if HMRC agrees the plan is affordable. HMRC expects you to reduce the debt as much as you can first, and it may ask directors to put in personal funds or accept lending. Late payment interest keeps running on what's unpaid. We compare the two routes in more detail in Time to Pay or a business loan.

Cash flow is often the reason companies borrow. A large Corporation Tax bill can put pressure on cash flow, particularly when payment is due before customer invoices have been paid. In iwoca's SME Expert Index, 61% of finance brokers named managing cash flow as the top reason for small business loan applications. That was up from 49% a year earlier.

If you're weighing up a tax loan, here's how an iwoca Flexi-Loan works. iwoca lends to limited companies only, from £1,000 to £1 million over up to five years, with a decision within 24 hours. You can repay early with no penalty. Every new Flexi-Loan needs a personal guarantee from at least one director. Borrowing only makes sense if the repayments fit your cash flow. If they don't, Time to Pay is likely to suit your company better.

To avoid the squeeze next year, see how to plan for your Corporation Tax bill.

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Corporation Tax deadlines: FAQs

Does HMRC send a Corporation Tax bill?

No. Your company works out its own Corporation Tax bill when it prepares the Company Tax Return. HMRC sends a 'notice to deliver your tax return' and reminders, which show your payment reference.

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Is late payment interest tax deductible?

Yes. HMRC treats late payment interest on Corporation Tax as an allowable expense for the accounting period it was incurred in.

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Does HMRC pay interest if you pay early?

Yes. HMRC says it'll pay you interest if you pay your Corporation Tax early.

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Do associated companies change the deadlines?

They can. The £1.5m and £20m instalment thresholds are divided between associated companies, so a smaller company in a group can still have to pay in instalments (gov.uk).

Sources (all checked 12 October 2026):

• Pay your Corporation Tax bill — gov.uk
• Company Tax Returns and penalties for late filing — gov.uk
• Pay Corporation Tax if you're a large company — gov.uk
• HMRC interest rates for late and early payments — gov.uk
• If you cannot pay your tax bill on time — gov.uk