The Most Common Tax Deductions UK Business Owners Forget to Claim

When it comes to reducing your tax bill, every allowable expense counts. But many UK business owners and self-employed individuals miss out on legitimate deductions simply because they don’t realise they can claim them.

Over time, these overlooked expenses can add up to hundreds or even thousands of pounds in unnecessary tax.

Here are some of the most common tax deductions UK business owners forget to claim, and how to make sure you’re not missing out.

What Counts as an Allowable Expense?

In general, an expense is allowable if it is incurred “wholly and exclusively” for business purposes, according to HMRC.

This means the cost must relate directly to running your business.

1. Working From Home Costs

One of the most commonly missed claims is home working expenses.

If you work from home, you may be able to claim a proportion of:

• Electricity and gas

• Broadband and phone bills

• Rent or mortgage interest

• Council tax

Alternatively, sole traders may use HMRC’s simplified flat-rate method.

Many people avoid claiming these because they’re worried about getting it wrong, but reasonable, properly calculated claims are completely acceptable.

2. Business Mileage

If you use your personal vehicle for business travel, you can usually claim mileage costs.

HMRC’s approved mileage rates currently allow:

• 45p per mile for the first 10,000 business miles

• 25p thereafter

Commonly forgotten journeys include:

• Trips to meet clients

• Temporary workplaces

• Networking events

• Visiting suppliers

Ordinary commuting generally cannot be claimed.

3. Use of Personal Mobile Phone and Internet

Many business owners use their personal phone and home internet for work, but forget to claim the business-use proportion.

You may be able to claim:

• Business calls

• A percentage of mobile contracts

• Internet costs relating to business activity

Keeping records or reasonable estimates helps support these claims.

4. Professional Subscriptions and Memberships

Certain professional memberships and subscriptions are allowable expenses, including:

• Trade body memberships

• Industry publications

• Professional software subscriptions

• Accounting software

If the membership is relevant to your business, it may qualify.

5. Bank Charges and Finance Costs

Business banking costs are frequently overlooked.

Possible claims include:

• Business bank account fees

• Card processing charges

• PayPal or Stripe fees

• Interest on business loans or overdrafts

Even small monthly fees can become significant over the course of a year.

6. Training Courses and Development

Training that helps maintain or improve existing business skills is generally allowable.

Examples may include:

• Industry refresher courses

• CPD training

• Online business courses

• Software training

However, training for entirely new skills or careers may not qualify.

7. Small Equipment and Office Supplies

It’s easy to forget smaller purchases made throughout the year, such as:

• Printers and ink

• Laptops and monitors

• Desk equipment

• Stationery

• Postage and packaging

These costs are often spread across many transactions, making them easy to miss without proper bookkeeping.

8. Staff and Client Refreshments

Basic refreshments for staff can often be claimed, including:

• Tea and coffee in the office

• Milk and biscuits for employees

• Water supplies

Business meals while travelling may also qualify in certain situations.

However, client entertainment rules are stricter, and many hospitality costs are not tax deductible.

9. Business Insurance

Business-related insurance policies are usually allowable expenses, including:

• Professional indemnity insurance

• Public liability insurance

• Employers’ liability insurance

• Cyber insurance

Some business owners forget these because they are annual rather than monthly costs.

10. Accountant and Bookkeeping Fees

Yes, your accounting fees themselves are generally tax deductible.

This may include:

• Annual accounts preparation

• Tax returns

• Payroll services

• Bookkeeping support

Many business owners are surprised to learn that professional accounting support can reduce their taxable profit.

Why Business Owners Miss So Many Expenses

The most common reasons include:

• Poor record keeping

• Mixing business and personal spending

• Leaving bookkeeping until year-end

• Not understanding HMRC rules

• Losing receipts or invoices

Using cloud accounting software can make a huge difference in tracking expenses consistently.

Final Thoughts

Claiming allowable expenses correctly is one of the simplest ways to reduce your tax bill legally and improve your business cash flow.

The key is keeping accurate records and understanding what you’re entitled to claim. Missing legitimate deductions means you could be paying more tax than necessary.

At Highway 61, we help UK business owners maximise allowable expenses while staying fully compliant with HMRC rules. Get in touch today to find out more.