Corporation Tax for UK Limited Companies: Complete Guide (2026)

Libin Lazar
Mar 5
2 min read

Corporation tax is one of the most important financial responsibilities for UK limited companies. Businesses must calculate and pay corporation tax on their profits every financial year.

Understanding how corporation tax works helps companies stay compliant with HMRC and avoid costly penalties.

What is Corporation Tax?

Corporation tax is a tax that UK limited companies must pay on their profits.

Profits may come from:

• Trading income• Investments• Selling assets for more than their cost

Every UK limited company must register for corporation tax when starting business activities.

Current Corporation Tax Rates in the UK

The corporation tax rate depends on the company’s profits.

Typical rates include:

• 19% for profits up to £50,000• 25% for profits over £250,000

Companies with profits between these amounts may qualify for marginal relief.

Corporation Tax Filing Deadlines

Companies must submit a Company Tax Return (CT600) to HMRC.

Important deadlines include:

• Register for corporation tax within 3 months of starting business• File tax return within 12 months after the accounting period ends• Pay corporation tax within 9 months and 1 day after the accounting period ends

Missing deadlines may result in penalties and interest charges.

Allowable Business Expenses

Limited companies can reduce corporation tax by claiming allowable expenses.

Common deductible expenses include:

• Office costs• Business travel• Staff salaries• Software and subscriptions• Professional services like accountants

Proper bookkeeping ensures these expenses are recorded correctly.

Why Good Bookkeeping Matters for Corporation Tax

Accurate financial records help businesses:

• Calculate correct profits• Track allowable expenses• Prepare accurate tax returns• Avoid HMRC penalties

Professional bookkeeping makes corporation tax preparation much easier.

How an Accountant Can Help

Many UK businesses work with accountants to manage corporation tax efficiently.

Professional accountants can help with:

• Preparing company tax returns• Calculating corporation tax• Filing with HMRC• Identifying tax-saving opportunities

This helps business owners focus on growing their company.

Conclusion

Corporation tax is a key responsibility for UK limited companies. Understanding tax rates, filing deadlines, and allowable expenses helps businesses stay compliant and manage their finances effectively.

Working with experienced accountants can make the process simpler and reduce the risk of errors.