What Is a CT600 Corporation Tax Return?
What is a CT600 Corporation Tax Return? Learn who must file, HMRC deadlines, penalties and how to submit your company tax return online in 2026.
R&D Tax Credits
R&D tax credits explained for UK companies. Check 2026 relief rates, eligibility, qualifying costs and HMRC claim rules. Includes a free R&D calculator.
Limited Company Tax
Limited company tax explained for 2026/27. Learn UK Corporation Tax rates, Marginal Relief, allowable expenses, dividends, deadlines and ways to reduce tax.
What is Tax Deductible
What is tax deductible? Learn which UK business expenses you can claim, what HMRC disallows and how allowable expenses can reduce your taxable profit.
Corporation Tax Payment Reference
Find your 17-character Corporation Tax payment reference, where to locate it in your HMRC account and what to do if you use the wrong reference.
When is Corporation Tax Due?
When is Corporation Tax due? Learn the 9 months and 1 day payment rule, CT600 filing deadlines, examples and key dates for UK limited companies.