Is your company paying Corporation Tax at the right rate?

The rate of Corporation Tax payable depends mainly on the level of a company’s taxable profits. The main rate is 25% and applies where profits exceed £250,000. Companies with profits of £50,000 or less generally pay Corporation Tax at the small profits rate of 19%. But note, these two thresholds will reduce if a company has associated companies.

The position is more complicated for companies with profits between these two thresholds. Where profits are between £50,000 and £250,000, Corporation Tax is charged at the 25% main rate, but marginal relief reduces the overall amount of tax payable. Accordingly, the effective rate increases gradually as profits rise, rather than jumping immediately from 19% to 25%.

This means that a company whose profits are just above £50,000 will not suddenly pay 25% Corporation Tax on all its profits but if there are profits are close to £250,000 they will pay tax at almost the 25% rate. In this way, the marginal relief results in a smoother transition between the two rates. 

Corporation Tax is initially calculated at the main rate of 25%, with marginal relief then deducted to arrive at the final liability. The relief is calculated using a standard fraction of 3/200.

Companies should check which rate applies when preparing their Corporation Tax calculation, particularly where profits are close to either threshold.

The thresholds can be affected by the number of associated companies, so a company should not assume that its profit figure alone determines the applicable rate. It is important to ensure that the correct amount of Corporation Tax is paid.
 

Source:HM Revenue & Customs | 07-09-2026
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Aitch
I'm Aitch, the Founder and CEO of CIGMA Accounting Ltd. As a Chartered Management Accountant and as a CIMA member, I've spent more than 16 years helping businesses, entrepreneurs, landlords, and individuals with tax planning, accounting, and HMRC compliance. As a chartered accountant in London, I'm passionate about making complex tax matters easier to understand and helping clients make confident financial decisions. Over the years, I've advised start-ups, SMEs, established companies, and high-net-worth individuals across a wide range of tax and accounting matters. My expertise includes Corporation Tax, Self-Assessment, Capital Gains Tax, Inheritance Tax planning, R&D tax relief, capital allowances, international tax, and resolving complex HMRC compliance issues. Whether clients need a business accountant, tax accountant, or strategic tax advisor, my focus is always on delivering practical advice that creates long-term value. One of my specialist areas is Making Tax Digital (MTD). I've worked extensively with businesses preparing HMRC's digital reporting requirements, helping them move to cloud accounting, improve financial processes, and adopt technology that makes compliance more efficient. I regularly speak at Making Tax Digital roadshows, industry events, and educational sessions in collaboration with Zoho Books, sharing practical insights into digital accounting, tax legislation, and the future of the profession. Many business owners looking for the best accounting firm in London are not simply searching for an accountant they're looking for trusted advice, responsive support, and long-term value. That's the approach I've taken in building CIGMA Accounting. My team and I work closely with businesses across London and the UK, providing accounting services, tax advisory, bookkeeping, payroll, VAT, company accounts, and strategic tax planning tailored to each client's goals. Through this website, I share practical guidance on UK taxation, Making Tax Digital, HMRC updates, Corporation Tax, Self-Assessment, and business finance. My aim is to provide reliable, straightforward information that helps business owners understand changing regulations, reduce compliance risks, and make informed financial decisions with confidence.