Plain-English guides to UK Corporation Tax and CT600 filing.
Late CT600 filing penalties explained: from 1 April 2026, £200 on day one and £400 at 3 months — doubled from previous rates. Plus 10% tax-geared penalties and 7.75% late payment interest. How to minimise the damage.
Calculate your CT600 filing deadline and Corporation Tax payment deadline. Different deadlines explained with examples for various accounting periods.
HMRC's free CT600 filing service closed on 31 March 2026. Here's exactly what to do if you haven't switched yet — step-by-step, no panic required.
HMRC's free CT600 filing service closed permanently on 31 March 2026. Here's your complete action plan — deadlines, penalties, and the most affordable alternative at £59.
When is your CT600 due? Filing deadlines, payment deadlines, and how they differ from Companies House deadlines. Avoid late penalties.
New limited company? Learn when to register for corporation tax, your first accounting period, filing deadlines, and how to avoid common first-year mistakes.
Complete 2026 guide to corporation tax for small businesses. Covers rates, allowable expenses, filing deadlines, payment dates, and tips to reduce your tax bill legally.