Corporation Tax Calculator for UK Limited Companies

Corporation tax rates for 2026/27

UK corporation tax depends on your company's profits. Small profits are taxed at 19%, profits above £250,000 at the 25% main rate, and profits in between get marginal relief, which produces an effective rate of 26.5% on the slice between the two limits.

Start with the calculator above

Enter your company's taxable profit for the accounting period into the corporation tax calculator above and it returns your estimated bill, applying the small profits rate, marginal relief or the main rate as appropriate. The sections below explain exactly how that figure is reached, so you can sense-check it rather than take it on trust.

How corporation tax is worked out

Corporation tax is charged on your company's profits, not its turnover. The plain-English formula is:

Corporation tax = taxable profit × the rate that applies to your profit level, minus any marginal relief.

Taxable profit is what you have left after deducting allowable business costs from your income. In words: Taxable profit = income (turnover plus any other gains) − allowable expenses − capital allowances. Allowable expenses are costs incurred wholly and exclusively for the business: staff wages, the director's salary, accountancy fees, software, business travel, rent and so on. Capital items such as laptops, tools and qualifying equipment are usually relieved through capital allowances rather than as a straight expense.

Once you have the taxable profit, HMRC applies one of three treatments. Below a lower profit limit, a lower small profits rate applies. Above an upper profit limit, the full main rate applies to all profits. Between the two limits, your company pays the main rate but receives marginal relief, which tapers the effective rate so it climbs gradually rather than jumping. The calculator handles that taper for you. Because these exact rates and limits are set by HMRC and can change at a Budget, always confirm the current figures on the official source linked below, and remember the limits are shared between associated companies under common control.

Corporation tax is the same across the whole UK. Unlike income tax, there is no separate Scottish rate, and unlike property tax there is no LBTT or LTT equivalent. A company in Glasgow, Cardiff or Belfast follows the same corporation tax rules as one in London. The regional split that matters for your personal taxes does not change the company's bill.

Worked example: turning turnover into a tax bill

Take Priya, who runs a one-person IT consultancy through her own limited company. In the year her company invoices clients £150,000. Her allowable costs are:

• Director's salary: £12,570
• Other overheads (insurance, software, subcontractor, accountancy, travel): £50,000
• A new laptop and equipment claimed in full as capital allowances: £8,000

Her taxable profit is £150,000 − £12,570 − £50,000 − £8,000 = £79,430. The calculator applies the corporation tax rate that fits a £79,430 profit and, because this sits between the lower and upper limits, it reduces the headline charge using marginal relief automatically. If Priya had instead spent another £5,000 on a genuine business cost before her year end, her taxable profit would fall to £74,430 and her bill would drop accordingly, which is why the timing of expenses matters.

A second, smaller company invoicing £40,000 with £15,000 of costs has a taxable profit of £25,000. With profits comfortably below the lower limit, the small profits rate applies and no marginal relief calculation is needed. The lesson: two companies with very different profits face very different effective rates, which is exactly what the calculator shows.

2026/27 corporation tax rates and limits

Corporation tax has three regimes depending on where your profit falls. The structure for the 2026/27 financial year is below. Because rates and the exact profit limits are set by the Government and can move at a Budget, check the live figures on gov.uk before you file.

The limits are divided by the number of associated companies, so a group with several companies hits the higher rate sooner. Confirm the current rates, limits and the marginal relief fraction on the official page: gov.uk corporation tax rates. Companies also have a separate deadline structure to income tax: corporation tax is normally due nine months and one day after the end of the accounting period, with the CT600 return filed within twelve months.

Taking money out: salary, dividends and the tax after corporation tax

Corporation tax is only the first layer. Profit left after the company has paid its tax belongs to the company until you extract it, usually as a director's salary, dividends, or a mix. Dividends can only be paid from post-tax retained profit, and they are then taxed on you personally on top of the corporation tax already paid.

For 2026/27 the first £500 of dividends is covered by the dividend allowance and taxed at 0%. Above that, dividends are taxed at 10.75% in the basic-rate band, 35.75% in the higher-rate band and 39.35% in the additional-rate band. These ordinary and upper rates rose by two percentage points for 2026/27, so the salary-versus-dividend balance is worth re-running. Our dividend vs salary calculator and dividend tax calculator show the personal tax on whatever you draw, and the limited company tax calculator brings the company and personal layers together. If you have taken money out informally during the year, check the rules with the director's loan calculator before your year end, because an overdrawn loan account can trigger an extra charge.

How to legally reduce your corporation tax

You cannot change the rate, but you can change the taxable profit it applies to. Practical, legitimate levers include:

• Claim every allowable cost. Genuine business expenses, the employer pension contributions your company makes, and the director's salary all reduce taxable profit.
• Use capital allowances. Qualifying equipment can often be relieved in full in the year of purchase. The capital allowances calculator shows how much you can claim.
• Time your spending. Bringing a planned purchase forward before the accounting period ends moves the relief into this year's bill.
• Check for innovation reliefs. If your company develops products, software or processes, you may qualify for enhanced relief; see the R&D tax credit calculator.
• Pay into a pension. Company pension contributions for directors are usually an allowable cost and stay out of your personal tax net.

For broader guidance on running a company tax-efficiently, the Government's corporation tax guidance and the free, impartial MoneyHelper service are good starting points.

Common mistakes that cost companies money

• Taxing turnover, not profit. Corporation tax never applies to your invoiced income, only to profit after allowable costs.
• Forgetting marginal relief. If your profit sits between the limits, applying the headline main rate overstates your bill. The calculator applies the taper.
• Ignoring associated companies. The profit limits are split across companies under common control, which can push you into the higher rate without you realising.
• Paying dividends out of pre-tax profit. Dividends come only from retained profit after corporation tax. Pay too much and you create an illegal dividend or an overdrawn director's loan.
• Missing the nine-month payment deadline. Corporation tax is due before the return is filed; late payment attracts interest.
• Mixing up the company and your self assessment. Dividends and salary still go on your personal self assessment tax return; the company's CT600 is separate.

These estimates are for guidance only and are not personal tax or financial advice. For a filing-ready figure, confirm the current rates on gov.uk or speak to a qualified accountant.

Related calculators worth a look

To see the full picture of what your company and you personally will pay, pair this with the limited company tax calculator, weigh how to extract profit with the dividend vs salary calculator, and tidy up any drawings using the director's loan calculator.

Related guides

Know the bill? Now read how to pay corporation tax: the 9-months-and-1-day deadline, reference numbers and payment methods.