How to Minimise Your Corporation Tax Liability Legally

Every limited company has a Corporation Tax liability once it makes a taxable profit, but very few pay only what the law requires. Missed expenses, unclaimed allowances and poorly timed decisions add up to real money every year. Reducing your Corporation Tax liability is not about schemes or loopholes. It is about claiming everything Parliament has made available, in the right year, with the records to back it up. This guide covers the legitimate ways UK companies can lower their Corporation Tax liability in 2026.

Start with how Corporation Tax is worked out

Corporation Tax is charged on taxable profits: your income minus allowable costs and reliefs. For the year from 1 April 2026, the rate is 19% on profits up to £50,000, 25% on profits over £250,000, with Marginal Relief in between. In the Marginal Relief band each extra pound of profit is effectively taxed at 26.5%, so a deduction there saves more than the same deduction above £250,000. Our guide to Corporation Tax rates for 2026 explains the bands in detail.

Every way of reducing your Corporation Tax liability works by either lowering taxable profit or claiming a credit against the tax.

1. Claim every allowable expense

A cost is allowable if it is incurred wholly and exclusively for the purposes of the trade. Common costs small companies forget include:

• accountancy, bookkeeping and payroll fees
• software subscriptions, website hosting and domain names
• business insurance, bank charges and card fees
• professional subscriptions and work-related training
• phone and broadband used for the business
• business travel, including mileage for directors using their own car, paid at HMRC's approved rates of 45p a mile for the first 10,000 business miles and 25p after that
• a share of home costs where directors work from home, under a proper arrangement

Client entertainment and most fines are not allowable. Staff entertainment, such as an annual party open to all staff, usually is.

2. Use capital allowances in full

Equipment, machinery, computers, vans and other plant and machinery are not deducted like ordinary costs. Instead you claim capital allowances, and the reliefs available to companies in 2026 are generous:

• Annual Investment Allowance (AIA): a 100% deduction on up to £1 million of qualifying spending each year.
• Full expensing: a 100% first-year allowance for companies buying new, unused main rate plant and machinery, with no upper limit.
• 50% first-year allowance: for new special rate assets, such as long-life assets and integral features.
• 40% first-year allowance: a new allowance for main rate spending from 1 January 2026, including assets bought for leasing.
• Writing-down allowances: for spending not covered above, at 14% a year for the main pool from April 2026 (down from 18%) and 6% for the special rate pool.

Cars are treated differently: most do not qualify for the AIA or full expensing, and the allowance depends on CO2 emissions. New zero-emission cars have had their own first-year allowance, so check the rules for the year you buy.

Timing matters

Capital allowances are claimed for the accounting period in which you incur the spending. Buying needed equipment just before your year end, rather than just after, brings the tax saving forward by a full year.

3. Make employer pension contributions

Pension contributions paid by the company for its directors and staff are usually an allowable expense, so they reduce your Corporation Tax liability. They are not taxed as income on the director when paid, and carry no National Insurance, as long as they stay within the annual allowance (generally £60,000 a year, including unused allowance carried forward from the previous three years in some cases). For owner-managers, this is often one of the most efficient ways to take value out of the company.

The contribution must be paid during the accounting period to be deducted in that period, and HMRC expects the total package to be reasonable for the work the director does.

4. Pay yourself a sensible salary

Directors' salaries are an allowable expense. Many owner-managers take a salary at around the National Insurance thresholds, then take the rest as dividends. Salary reduces Corporation Tax but can bring employer and employee National Insurance; dividends do not reduce Corporation Tax but carry no National Insurance.

From April 2025 employer National Insurance is 15% on earnings above £5,000 a year. The Employment Allowance of £10,500 can offset that, but it is not available to a company whose only employee paid above the threshold is a director. With dividend tax rates rising to 10.75% and 35.75% from April 2026, it is worth recalculating the best mix this year rather than repeating last year's figures.

5. Claim research and development relief

R&D relief is not just for laboratories. Companies that try to resolve scientific or technological uncertainty, such as developing new software, processes or products, may qualify. For accounting periods starting on or after 1 April 2024, most companies claim under the merged scheme, which gives an above-the-line expenditure credit of 20% of qualifying costs. Loss-making companies that spend heavily on R&D may qualify for enhanced support instead.

HMRC has tightened its checks on R&D claims, and you must usually tell HMRC in advance if you are claiming for the first time. A good claim is backed by a clear technical explanation of the uncertainty you tried to resolve.

6. Use your losses wisely

If your company makes a trading loss, it does not simply disappear. You can usually:

• set it against other profits of the same period
• carry it back against profits of the previous 12 months, which can lead to a refund of Corporation Tax already paid
• carry it forward against future profits

Carrying back gives cash now; carrying forward can save more if future profits fall in the Marginal Relief band. The best choice depends on your figures.

7. Offer tax-efficient benefits

Some benefits cost the company less in tax than paying the same value as salary:

• Trivial benefits: gifts costing £50 or less that are not cash or a reward for work are tax-free, with an annual cap of £300 for directors of close companies.
• Electric company cars: the benefit in kind rate for zero-emission cars remains low, which can make them cheaper than funding a car through salary.
• Annual staff events: up to £150 a head per year is tax-free for the employees.

8. Do not forget timing and accounting choices

Several decisions shift profit between years without changing the total:

• accruing costs you have incurred but not yet been invoiced for
• writing off debts that are genuinely unlikely to be paid
• valuing stock and work in progress correctly at the year end
• choosing your accounting reference date

These do not reduce the tax for ever, but they make sure profit is taxed in the right year, which matters around the Marginal Relief limits.

9. Give to charity through the company

Cash donations from a company to a registered charity are deducted from taxable profits, so they reduce your Corporation Tax liability in the year they are paid. Unlike Gift Aid for individuals, the relief goes to the company, not the charity. Gifts of equipment or stock the company used in its trade can also qualify. Keep the charity's confirmation of the gift with your records.

10. Check whether the Patent Box applies

Companies that own or exclusively license qualifying patents, and that did significant development work on them, can elect into the Patent Box. Profits linked to the patented invention are then taxed at an effective 10% instead of up to 25%. It suits a small number of businesses, but for those it fits, the saving can be large.

What not to do

Lowering your Corporation Tax liability must stay within the law. Avoid:

• putting personal costs through the company; they are a benefit in kind or a director's loan, not a business expense
• marketed tax avoidance schemes promising unusually large savings; HMRC publishes warnings about them and the penalties can be severe
• overdrawn director's loan accounts left unpaid nine months after the year end, which trigger an extra charge of 33.75% of the loan
• claiming without records; every expense needs evidence

Keep good records all year

None of these reliefs help if the paperwork is missing. HMRC can ask to see evidence for any figure in your Company Tax Return, and companies must keep their records for at least six years. Store invoices and receipts digitally as you go, keep a mileage log, and record the reason for unusual spending at the time. Good records turn a tax enquiry from a worry into a formality.

Reducing your Corporation Tax liability: a checklist

• Review expenses for anything missed, especially subscriptions and mileage.
• Plan equipment purchases before your year end and claim the right allowance.
• Consider employer pension contributions for directors.
• Recheck your salary and dividend mix for the 2026 rates.
• Ask whether any of your work could qualify for R&D relief.
• Use losses in the period that saves the most tax.

HMRC lists the main allowances on GOV.UK under claiming capital allowances.

Let us keep your Corporation Tax liability as low as the law allows

We prepare your accounts, review every expense and allowance, and talk through pension, salary and dividend options before your year end, then file your CT600 on time. See our Corporation Tax service to find out more.