corporation tax calculator
Use our Corporation Tax Calculator to estimate how much tax your UK limited company may owe based on your annual profits. Whether you’re a small business or a growing company, this easy-to-use calculator applies the latest 2025/26 tax rates, including marginal relief, to give you a quick and accurate view of your expected Corporation Tax bill. Simply enter your profit before tax and get an instant estimate no signup or downloads required.
Based on HMRC’s official rules for Corporation Tax rates and Marginal Relief: Rates and allowances Corporation Tax (gov.uk) and Marginal Relief for Corporation Tax (gov.uk).
Corporation Tax Calculator 2025/26
Corporation Tax: What It Is, Why Compliance Matters, and How a Corporation Tax Calculator Helps
Corporation tax is the tax that UK limited companies and certain organisations pay on their taxable profits. It covers trading income, investment returns, and chargeable gains, after deducting allowable expenses, capital allowances, and any reliefs. Companies file returns on a CT600 for each accounting period.
Staying compliant matters because timely, accurate returns and payments protect your business from HMRC penalties and interest. Good compliance also reduces the risk of intrusive enquiries and preserves access to valuable reliefs such as loss offsets, R&D, and capital allowances. It strengthens cash-flow forecasting and dividend planning, and it signals reliability to lenders, investors, suppliers, and customers.
Strong tax processes improve management information and board decision-making. They encourage disciplined reviews of revenue recognition, director remuneration, intercompany recharges, and balance-sheet provisions.
In practice, using a corporation tax calculator alongside robust bookkeeping helps you estimate liabilities early. You can model scenarios rate changes, marginal relief thresholds, asset purchases, or loss carry-backs so you set aside the right cash and avoid year-end surprises. Tie those estimates to your finance calendar to ensure payments are made on time, including quarterly instalments for large companies, and support the return with clear working papers.
Ultimately, corporation tax compliance is not just a statutory obligation; it is a foundation for sustainable growth. It supports better valuations and smoother due diligence. It enables owners to reinvest with confidence, reward teams responsibly, and demonstrate sound governance. Combined with proactive advice from qualified accountants and the regular use of a corporation tax calculator, it turns tax from a once-a-year scramble into a predictable, well-managed business process.
Important note: Our calculators provide indicative estimates only and may not be 100% accurate. Before making any financial or tax decisions, please consult a qualified, certified accountant, online calculators do not constitute advice.
