How Much Corporation Tax Will My Small Limited Company Pay in 2026/27?

For the 2026/27 tax year (the financial year beginning 1 April 2026), a small limited company pays Corporation Tax at 19% if its taxable profits are £50,000 or less. Profits above £250,000 are taxed at the main rate of 25%, and profits between the two limits are taxed at 25% less marginal relief, which produces an effective rate somewhere between 19% and 25%. The tax itself is due nine months and one day after your accounting period ends.

Below, our London team explains the 2026/27 rates in plain English, works through a realistic example, sets out the deadlines every director should have in the diary, and covers what happens if you miss one.

What are the Corporation Tax rates for 2026/27?

HMRC’s published rates and allowances confirm that the Corporation Tax regime for the financial year starting 1 April 2026 is unchanged from the previous year:

• Small profits rate — 19%: applies where taxable profits are £50,000 or less.
• Main rate — 25%: applies where taxable profits are more than £250,000.
• Marginal relief: applies between £50,000 and £250,000, using a standard fraction of 3/200. Your company pays the main rate on its profits but deducts a relief that tapers away as profits rise.

Two wrinkles catch owners out. First, the £50,000 and £250,000 limits are divided between associated companies — so if you control two companies, each gets limits of £25,000 and £125,000. Second, the limits are reduced proportionately for accounting periods shorter than 12 months. If either applies to you, it is worth getting the sums checked before you budget for the bill.

How does marginal relief work?

If your profits fall between the limits, you do not simply pay a blended rate. Instead, you calculate tax on all profits at 25%, then subtract marginal relief, worked out as the difference between the £250,000 upper limit and your profits, multiplied by 3/200. The result is that every pound of profit between £50,000 and £250,000 effectively suffers tax at 26.5% — which is exactly why planning around this band matters for growing companies.

Worked example: £80,000 profit in 2026/27

Take a London limited company with a year ending 31 March 2027, taxable profits of £80,000, no associated companies and a full 12-month period:

• Tax at the main rate: £80,000 × 25% = £20,000
• Marginal relief: (£250,000 − £80,000) × 3/200 = £2,550
• Corporation Tax due: £20,000 − £2,550 = £17,450

That is an effective rate of roughly 21.8% — noticeably more than 19%, but well below the headline 25%. You can test your own numbers in seconds with our free Corporation Tax Calculator 2026/27.

What are the deadlines for accounts and Corporation Tax?

A private limited company has three separate deadlines, and they do not all fall on the same day:

• Annual accounts to Companies House: 9 months after your financial year ends (your very first accounts are due 21 months after the date of incorporation).
• Pay Corporation Tax (or tell HMRC none is due): 9 months and 1 day after your Corporation Tax accounting period ends.
• File your Company Tax Return (CT600): 12 months after the end of the accounting period.

Sticking with the example above: a 31 March 2027 year end means accounts are due at Companies House by 31 December 2027, Corporation Tax must be paid by 1 January 2028, and the CT600 must be filed by 31 March 2028. Notice the oddity — the payment deadline arrives before the filing deadline, so in practice the tax computation needs to be finished well before the return is due.

What happens if you miss a deadline?

Companies House charges automatic penalties for late accounts: £150 if you are up to a month late, £375 at one to three months, £750 at three to six months and £1,500 beyond six months — and these double if your accounts are late two years in a row. HMRC separately charges £200 the day the Company Tax Return is late, a further £200 at three months, and once you are six months late it estimates your bill and adds a penalty of 10% of the unpaid tax, with another 10% at twelve months. Interest also runs on Corporation Tax paid late, so an overlooked year end can become expensive quickly.

Can you legitimately reduce the bill?

Yes — Corporation Tax is charged on taxable profit, not turnover, so making sure every allowable cost is claimed is the first step: salaries, employer pension contributions, software, travel, professional fees and use-of-home claims are commonly missed or under-claimed. Capital allowances on equipment, the timing of expenditure around your year end, and the structure of director pay all affect the final figure too. This is the day-to-day work of our accounts and Corporation Tax return service, where we prepare the statutory accounts and CT600 together and look for reliefs before anything is filed.

For the official rules and current figures, see GOV.UK’s guidance on Corporation Tax rates and reliefs.

Frequently asked questions

What Corporation Tax rate does a small limited company pay in 2026/27?

If taxable profits are £50,000 or less, the small profits rate of 19% applies. Profits over £250,000 pay the 25% main rate, and profits in between pay 25% reduced by marginal relief, giving an effective rate between 19% and 25%.

When is Corporation Tax due for 2026/27?

Corporation Tax must be paid 9 months and 1 day after the end of your accounting period, and the Company Tax Return (CT600) must be filed within 12 months of the period end. For a 31 March 2027 year end, that means payment by 1 January 2028 and filing by 31 March 2028.

Do I still need to file a return if my company made a loss?

Yes. You must file a Company Tax Return even if no tax is due, and you should tell HMRC that nothing is owed by the payment deadline. Filing also records the loss, which can usually be carried forward or back to reduce tax in other years.

Written by the Accountactical Team — ACCA-Approved Accountants, London.

This article is general information for UK small-business owners, not formal tax advice — please speak to an accountant about your own circumstances before acting on it.