Corporation tax can be a daunting topic for many small business owners, but understanding how it works is essential to remain compliant and financially prepared. As we move through 2025, changes to tax thresholds and deadlines make it even more important to stay informed. In this guide, we break down the basics of corporation tax, recent updates, and how you can plan effectively with the help of a trusted accountancy partner like David Proctor Accountancy.
What Is Corporation Tax?
Corporation tax is the tax that limited companies in the UK pay on their taxable profits. This includes money made from trading, investments, and selling assets for more than they cost (capital gains). Unlike personal income tax, there is no tax-free allowance — every pound of profit is subject to corporation tax.
Current Corporation Tax Rates for 2025
As of April 2023, the UK introduced a two-tiered system for corporation tax:
- Small Profits Rate (19%) – For companies with profits of £50,000 or less.
- Main Rate (25%) – For companies with profits above £250,000.
- Marginal Relief – Applies to businesses with profits between £50,001 and £250,000, creating a gradual increase from 19% to 25%.
This structure remains in place for 2025, and it’s vital that businesses calculate their liability accurately — especially if profits fall within the marginal band.
Filing Deadlines and Payment Dates
Corporation tax deadlines can be confusing, as filing your return and paying the tax are two separate dates:
- Tax payment is due 9 months and 1 day after the end of your accounting period.
- The company tax return (CT600) must be filed within 12 months of your year-end.
Missing these deadlines can lead to interest charges and HMRC penalties, so having a clear calendar and timely financial reporting is crucial.
What You Can Deduct
Reducing your tax bill legally is possible through allowable expenses. Common examples include:
- Staff salaries
- Office costs (rent, utilities)
- Business insurance
- Professional fees (including accountancy services)
- Marketing and advertising
- Software and technology subscriptions
Keeping detailed records and ensuring expenses are wholly for business use is key. David Proctor Accountancy can help you identify all deductible costs you might otherwise miss.
Planning Ahead: Tips for Managing Corporation Tax
- Estimate Your Tax Bill Early
Don’t wait until the last minute. Regular management accounts can help you project profits and set aside funds accordingly. - Use Marginal Relief Calculators
For companies in the marginal relief range, understanding how much you’ll owe can be complex. We use HMRC’s calculator and bespoke tools to ensure accuracy. - Claim R&D Tax Relief (if applicable)
If your business is innovating, you may be eligible for Research and Development tax credits — a valuable incentive many businesses overlook. - Review Your Structure
Could a change in shareholding, salary vs. dividend structure, or reinvestment approach improve your tax efficiency? We’ll guide you. - Book a Mid-Year Tax Review
Waiting until year-end is risky. A review mid-way through your accounting period lets us adjust strategies and maximise savings.
Why Work with David Proctor Accountancy?
Staying compliant is just the start. At David Proctor Accountancy, we go beyond simple filings to provide proactive tax planning, tailored advice, and reliable support that helps your business grow. Whether you’re just starting or scaling up, we ensure your corporation tax obligations are met — efficiently and stress-free.
