Corporation tax is one of the biggest costs for UK businesses. And in 2026, with updated rules and allowances in play, SMEs that are not planning ahead are likely to overpay.
The good news is that HMRC provides a wide range of legal reliefs, deductions, and allowances specifically designed to reduce your tax bill.
This guide covers the most effective steps your business can take to reduce corporation tax legally, improve cash flow, and stay fully compliant with HMRC.
1. Understand Your Corporation Tax Rate
Before planning anything, know where your business sits.
For the 2026/27 financial year:
- Small profits rate: 19% on profits up to £50,000
- Main rate: 25% on profits over £250,000
- Marginal relief applies for profits between £50,001 and £250,000
Knowing your rate helps you identify which allowances and reliefs will have the biggest impact on your tax position.
2. Claim All Allowable Business Expenses
HMRC allows you to deduct genuine business expenses from your taxable profits. Common examples include:
- Employee salaries, bonuses, and pension contributions
- Office rent and utilities
- Marketing and advertising costs
- Business travel and vehicle expenses
- Professional fees such as accountants and solicitors
Important: Keep detailed records of all expenses. HMRC can request proof during an inspection, and missing documentation can result in a disallowed claim.
3. Make the Most of Capital Allowances
Capital allowances let you claim tax relief on business assets over time instead of expensing them all at once.
Qualifying assets include:
- Machinery and equipment
- Computers and IT systems
- Vehicles used for business purposes
Annual Investment Allowance (AIA): In 2026, businesses can claim up to £1 million on qualifying assets in a single year.
Capital allowances are one of the most straightforward ways to reduce taxable profits legally, and many SMEs do not claim their full entitlement.
4. Claim Research and Development Tax Relief
If your business develops new products, software, processes, or services, you may qualify for R&D tax relief under the UK’s Merged R&D Scheme introduced from April 2024.
Key points:
- The standard RDEC rate is 20% of qualifying R&D expenditure
- Loss-making R&D-intensive SMEs may qualify for 27% under the Enhanced R&D Intensive Support (ERIS) scheme
- You must demonstrate genuine innovation and technical or scientific uncertainty
- The claim is made through your corporation tax return
Many UK businesses miss this relief entirely. If your team is solving technical problems or building something new, it is worth checking your eligibility.
5. Use Losses Strategically
A business loss is not just a setback. It is also a tax planning tool.
- Carry forward losses: Offset against future profits with no time limit
- Carry back losses: Offset against profits from the previous accounting year
With proper loss management, you can significantly reduce your corporation tax liability in difficult trading years, sometimes down to zero.
6. Consider Pension Contributions
Employer pension contributions are fully tax-deductible and reduce your company’s taxable profits immediately.
Benefits include:
- Immediate reduction in corporation tax
- Financial benefit for directors and employees
- Director pension contributions can be particularly tax-efficient when planned well
Pension planning is not just a tax-saving strategy. It is also a long-term wealth-building tool for business owners.
7. Invest in Energy-Efficient Equipment
Since April 2023, businesses can claim a 100% First Year Allowance (FYA) on qualifying energy-efficient assets, including:
- Solar panels and renewable energy systems
- Zero-emission vehicles
- Energy-saving machinery and technology
This reduces your taxable profits in the year of purchase and supports your sustainability commitments at the same time.
8. Consider Structuring Your Business Efficiently
How your business is structured can have a significant impact on your overall tax position.
Things worth reviewing with your accountant:
- Dividends vs salary: A combination of salary and dividends can reduce your overall tax and National Insurance burden
- Group relief: If you operate multiple companies, profits and losses can be offset across the group
- Holdings and subsidiaries: Strategic structuring may open up additional tax planning options
Always take professional advice before making structural changes. HMRC compliance must come first, and any arrangement must be commercially justified.
9. Do Not Overlook Charitable Donations
Corporate donations to HMRC-registered charities are fully tax-deductible.
- Deduct the full value of the donation from your taxable profits
- Contributes to your corporate social responsibility profile
- Can make a meaningful difference to your tax bill when planned in advance
10. Work With a Tax-Savvy Accountant
Corporation tax planning involves a lot of moving parts. A knowledgeable accountant will:
- Identify reliefs and allowances your business qualifies for
- Ensure all claims are accurate and compliant with HMRC
- Help you plan ahead rather than react at year-end
- Potentially save you far more than their fee
For many UK SMEs, outsourcing to a specialist accounting firm is more cost-effective than overpaying tax year after year.
Conclusion
Reducing corporation tax legally is not about loopholes. It is about awareness, planning, and working with the right people.
By claiming allowable expenses, using capital allowances, making pension contributions, and exploring R&D relief, your business can keep more of its profit in 2026 and beyond.
Do not wait until your filing deadline. The best tax planning happens throughout the year, not at the end of it.
Ready to Reduce Your Corporation Tax Bill?
Book a free 15-minute consultation with our UK accounting specialists at SustainEdge Global.
We will review your finances and identify tax-saving opportunities tailored to your business.
