Small Business Tax Deductions in the UK: Top Claims for 2025

Understanding small business tax deductions is one of the most powerful ways to reduce your tax bill and keep more money in your business. In 2025, the UK government continues to support small business growth through a range of valuable reliefs and allowable expenses. Whether you’re a sole trader, limited company, or SME, knowing which deductions you’re entitled to can make a significant difference to your bottom line. Read on to explore every key deduction available to you this year.

Allowable Expenses – Core Small Business Tax Deductions

Know that there are several expenses that you can claim as a small business. Some of these include expenses on office supplies and equipment, employee wages, business insurance premiums, utility bills, marketing, and advertising. It is also possible to claim certain employee benefits, such as health insurance, pensions, and childcare vouchers as your business expenses.

Here one should not forget to mention that these allowable expenses also include the much-needed vehicle and travel expenses. Regardless of the mode of transport used for business trips, you can also claim expenses for repairs, servicing, and road tax. Moreover, if you use your personal vehicle for business trips, you will become eligible to claim 45p per mile for the first 10,000 miles and then 25p per mile.

Small Business Rate Relief — A Key Tax Saving

Does your business run from your property whose rateable value is less than £12,000? If yes, rejoice because your business is eligible for 100 % small business rate relief, leading to massive savings. However, you need to contact your local council. This relief will taper down gradually if the rateable value is between £12,001 and £15,000.

Marginal Rate Relief

If your SME is a limited company, you can apply for the marginal rate relief to reduce your corporation tax. The only condition is that your taxable profits from 1 April 2023 must be between £50,000 and £250,000. Thus, under this marginal rate relief, you will be required to pay a tax rate between 19% and 25%, which will gradually increase by an increase in your taxable profit.

Seed Enterprise Investment Scheme (SEIS)

While SEIS does not directly help tax deductions, it attracts investors. So, you can secure funding for your SME through this scheme, which will eventually help the investors to avail a range of tax reliefs such as 50% income tax relief, capital gains tax exemption, etc.  

Research & Development (R&D) Tax Credits

If your small business is developing innovative products, services or processes or improving existing ones, you can claim up to 27% of your R&D costs. This covers staff wages, utilities for R&D work, software, etc. Meanwhile, your small business can become eligible to claim expenses on some qualifying indirect activities such as maintenance of R&D equipment and research by students and researchers.

Living at Your Business Premises

Are you running a Bed and Breakfast, guesthouse, or small care home? In such a case, instead of manually calculating private vs. business use, you can claim business expenses using HMRC’s simplified expenses flat rate. Normally, when you run a business from your home, you have to separate your business costs from personal costs for certain things like electricity, gas, and council tax. As this is extremely tough, HMRC provides a fixed monthly deduction based on the number of people living there. So, let you live with your spouse and two kids in a guesthouse that you run as a small business, the flat rate for 3 or more people will apply which is £650 per month.

Annual Investment Allowance – A Vital Small Business Tax Deduction

Starting a small business means investing in some plants and machinery for operations, but they often prove very costly. Here comes to your rescue the annual investment allowance. This allowance enables you to deduct the costs of all these plants and machinery up to 1 million from your business profits before paying any tax and reducing your taxable income.

Staying on top of your small business tax deductions in 2025 can save you thousands of pounds each year. Keeping accurate records, retaining receipts, and working with a qualified accountant ensures you claim every eligible expense while remaining fully compliant with HMRC regulations. If you’d like tailored advice on small business tax deductions, our expert team at CoreAdviz is ready to help — from VAT registration and bookkeeping to tax planning and self-assessment tax return submissions. You’re never alone in your business journey.