Register

Corporation tax rates and marginal relief for 2026 to 2027

For the financial year starting 1 April 2026 the small profits rate is 19% on profits up to £50,000 and the main rate 25% on profits over £250,000, with marginal relief between.

Accountin · Last checked 2 October 2026

Questions

How is marginal relief worked out?

Using the standard fraction of 3/200, for profits between the lower limit of £50,000 and the upper limit of £250,000.

How do associated companies change the limits?

The limits are divided by the number of associated companies plus one, and reduced proportionately for an accounting period shorter than 12 months.

When is the tax paid?

9 months and 1 day after the end of the accounting period, for profits up to £1.5 million. Larger companies pay in instalments.

How does Accountin work it out?

The CT600 applies the rates and marginal relief for each financial year the period falls in, with the limits divided for associated companies.

Accountin is opening to its first practices

Register your practice and we will contact you to set up your account.

Register your practice