10 Allowable Expenses UK Small Businesses Are Missing in 2026

By Jessica

Running a small business in the UK has never been more dynamic. As we navigate 2026, the tax landscape continues to evolve, making it more important than ever to ensure you are claiming every penny you are legally entitled to. Whether you are a sole trader or a limited company director, "allowable expenses" are the key to reducing your taxable profit and, ultimately, your tax bill.

The Golden Rule remains the same: an expense is generally allowable if it is incurred wholly and exclusively for the purposes of your trade. However, many business owners miss out on thousands of pounds every year simply because they aren't aware of what qualifies.

In this guide, we break down the top 10 allowable expenses that UK small businesses frequently overlook.

If you want to strengthen your understanding of the core rules behind deductions and compliance, our Small Business Tax 101: A Beginner's Guide to Mastering Your Finances guide is a useful companion read.

1. Home Office Expenses

With hybrid working now the standard, many business owners forget to claim for the space they use at home. How you claim this depends on your business structure.

• Sole Traders: You can use "simplified expenses" based on the hours you work from home. For 2026, this ranges from £10 per month (25–50 hours) to £26 per month (101+ hours). Alternatively, you can calculate the actual proportion of your rent, mortgage interest, council tax, and utilities used for business.

• Limited Company Directors: You can pay yourself a flat rate of £6 per week (roughly £312 per year) tax-free without needing to provide receipts. If your actual costs are higher, you can draw up a rental agreement between yourself and your company, though this requires careful handling to avoid personal tax implications.

2. Mileage and Business Travel

While you cannot claim for your "ordinary commute" between home and a permanent place of work, almost all other business-related travel is claimable.

HMRC's approved mileage rates are a popular choice. For most vehicles, you can claim 45p per mile for the first 10,000 miles and 25p thereafter. Don't forget that you can also claim 20p per mile for business travel on a bicycle! Beyond mileage, remember to keep receipts for parking, tolls, congestion charges, and train fares.

3. Professional Fees

Many entrepreneurs think they can only claim for direct business costs like stock or hardware. However, the cost of professional advice is fully allowable. This includes fees for:

• Accountants and Bookkeepers

• Solicitors (for business-related contracts or disputes)

• Tax advisors

• Surveyors (for business premises)

Investing in a Limited Company Accountant often pays for itself through the tax savings they identify.

4. Training and Development

In 2026, staying ahead of the curve is vital. HMRC allows you to claim for training courses that update or reinforce existing skills used in your business.

If you are a web designer taking a course on the latest AI-driven UI tools, that is generally allowable. However, if you are a plumber taking a course to become a pilot, HMRC considers that "new skills" and won't allow the deduction. Subscriptions to professional journals and membership fees for HMRC-approved professional bodies are also claimable.

5. Equipment and Technology (Capital Allowances)

From laptops to specialized machinery, the tools you use to run your business are deductible. Small items like keyboards or stationery are usually treated as revenue expenses. Larger items are claimed via Capital Allowances.

The Annual Investment Allowance (AIA) allows most small businesses to deduct 100% of the cost of qualifying plant and machinery in the year of purchase. Always check with an expert to see if your latest tech upgrade qualifies for immediate relief.

6. Business Insurance

Insurance is a mandatory cost for many, yet some forget to include it in their tax return. You can claim for:

• Public Liability Insurance

• Professional Indemnity Insurance

• Employers’ Liability Insurance

• Content insurance for business premises

• Professional fee protection insurance

If you have a home-based business, you may be able to claim a proportion of your home insurance if it covers business use.

7. Bank Charges and Interest

If you use a dedicated business bank account, all your monthly fees and transaction charges are allowable. More importantly, if you have a business loan or a business credit card, the interest on those payments is also deductible.

One common mistake is using a personal account for business and failing to separate the charges. Keeping your finances distinct makes this much easier to track.

8. Software Subscriptions

The shift to "Software as a Service" (SaaS) means most businesses have a dozen or more monthly subscriptions. From your VAT-compliant accounting software to CRM systems, project management tools, and even cloud storage like Dropbox or Google Drive: all of these are allowable expenses.

If you use a tool for both personal and business reasons (like a premium LinkedIn account), you should only claim the portion that relates to your business.

9. Pension Contributions

This is one of the most tax-efficient ways to move money out of your business.

• Limited Companies: Contributions made by the company into a director’s pension are usually treated as an allowable business expense, which reduces your Corporation Tax.

• Sole Traders: While not a "business expense" in the same way, you receive tax relief on your personal contributions, which effectively reduces the amount of Income Tax you pay.

10. Charitable Donations

Supporting a good cause isn't just good for the soul; it can be good for your tax position too.

• Limited Companies: Donations to UK registered charities are deducted from your total profits before Corporation Tax is calculated.

• Sole Traders: You don't claim these as a business expense, but you get tax relief through Gift Aid, which increases your basic rate tax band.

For a broader look at claiming costs correctly and handling self-employed tax responsibilities, see The Ultimate Guide to Tax Returns for Self Employed: Everything You Need to Succeed.

Why Records Matter

HMRC requires you to keep records of your expenses for at least six years. In 2026, digital record-keeping is the standard under the Making Tax Digital (MTD) initiative. Using apps to scan receipts the moment you receive them ensures you never lose a "missing" expense again.

How to Find Every Saving

Identifying every allowable expense can be time-consuming and complex. The rules often change, and what was allowable last year might have different thresholds today. This is where professional expertise becomes invaluable.

At Accountant Search, we help UK small businesses find the perfect accounting partner to navigate these rules. A good accountant doesn't just file your returns; they act as a strategic partner, ensuring you remain compliant while maximizing your take-home pay.

If you’re unsure whether you’re claiming everything you can, why not speak to a local expert? We can match you with qualified accountants who specialize in SME tax services, helping you keep more of what you earn in 2026 and beyond. If you are still comparing providers, read Accounting Services UK: The Complete Guide to Finding the Right Accountant for Your Business for more help choosing the right fit.