If you run a UK limited company, claiming allowable expenses correctly can make a significant difference to your Corporation Tax bill. Many directors across England, Scotland and Wales overpay tax simply because they are unsure what HMRC allows — or how to calculate certain expenses properly.

This local UK guide explains what expenses a limited company can claim, how HMRC expects them to be calculated, and how to stay compliant while reducing tax legally.

What Are Allowable Expenses for a UK Limited Company?

HMRC defines allowable expenses as costs that are “wholly and exclusively” for business purposes.

These expenses are deducted from your company’s income before Corporation Tax is calculated — which means lower taxable profits and less tax to pay.

If an expense has both business and personal use, only the business portion can be claimed.

Why Claiming Expenses Correctly Matters in the UK

Correct expense claims help your limited company:

• Reduce Corporation Tax legally
• Avoid HMRC penalties and enquiries
• Improve cash flow
• Keep accounts accurate and compliant

Incorrect or unsupported claims are one of the most common reasons HMRC opens investigations into small limited companies.

Common Allowable Expenses for UK Limited Companies

Office & Day-to-Day Business Costs

You can usually claim:

• Office rent
• Business rates
• Electricity, gas, and water
• Business phone and internet
• Stationery and printing
• Accounting and bookkeeping software

These must relate directly to running your business.

Salaries, Wages & Staff Costs

Fully allowable staff costs include:

• Directors’ salaries
• Employee wages
• Employer’s National Insurance
• Workplace pension contributions
• Bonuses
• Work-related training

Training must support your existing business activities, not a new trade.

Director Expenses (UK Guidance)

Directors can claim:

• Business travel
• Mileage using HMRC rates (currently 45p per mile for the first 10,000 miles)
• Hotels for business trips
• Meals while travelling for work
• Professional subscriptions related to the role

Personal expenses must never be claimed through the company.

Travel & Vehicle Expenses

Allowable travel costs include:

• Fuel for business journeys
• Mileage for personal vehicles
• Public transport fares
• Parking fees
• Business vehicle insurance
• Servicing and repairs (business use only)

 Travel between home and your normal place of work is not allowable.

Marketing, Advertising & Website Costs

You can claim for:

• Website design and hosting
• Domain names
• SEO services
• Google Ads and social media advertising
• Branding and logo design
• Flyers and promotional materials

Marketing expenses are fully allowable when used to promote the business.

Professional Fees & Subscriptions

Allowable professional costs include:

• Accountant and tax advisor fees
• Legal fees related to business
• Company secretarial services
• Professional body subscriptions (ACCA, ICAEW, etc.)

Computers, Software & Equipment

You can claim:

• Laptops and desktops
• Printers and office equipment
• Business mobile phones
• Software subscriptions

Some equipment may qualify for capital allowances, spreading tax relief over time.

Business Insurance

Allowable insurance expenses include:

• Employers’ liability insurance
• Professional indemnity insurance
• Public liability insurance
• Business contents insurance

Use of Home as Office (UK Limited Company Guidance)

If you run your limited company from home, HMRC allows you to claim a reasonable proportion of household costs — but it must be calculated carefully.

There are two HMRC-accepted methods:

Method 1: Flat Rate (Simplified Method)

Your limited company can pay you a fixed monthly amount without detailed calculations:

• £26 per month (£312 per year)

This covers basic household running costs and is simple to apply.
No receipts are required, but you must actually work from home.

 Simple
 Low risk
 Often underclaims the real cost

Method 2: Actual Cost Method (Proportionate Calculation)

This method allows higher claims but requires clear calculations.

Step 1: Identify Relevant Household Costs

You can include:

• Electricity and gas
• Water
• Council tax
• Internet
• Rent or mortgage interest only (not capital repayments)

 Do not include personal expenses like food or TV subscriptions.

Step 2: Calculate Business Use Percentage

You usually calculate this based on:

Number of rooms used for business ÷ total rooms × time used for business

Example:

• 1 room used as office
• 5 rooms in the house
• Used 8 hours a day, 5 days a week

Business use calculation:
1 ÷ 5 = 20%
20% × time usage (e.g. 40% of the week)
Final claim = 8% of household costs

Step 3: Claim Through the Company

Your limited company reimburses you for the calculated amount and records it as a business expense.

 Important:

• Avoid claiming exclusive business use unless the room is never used personally
• Incorrect claims can cause Capital Gains Tax issues when selling your home

This method should ideally be reviewed by a UK accountant.

Expenses You Cannot Claim

HMRC does not allow:

• Personal expenses
• Client entertaining
• Fines or penalties
• Everyday clothing
• Political donations

Keep Proper Records for HMRC

To stay compliant:

• Keep receipts and invoices
• Use a business bank account
• Maintain bookkeeping records
• Retain records for at least 6 years

Final Thoughts: UK-Focused Tax Efficiency

Claiming allowable expenses properly is one of the most effective ways to reduce Corporation Tax in the UK — but only if done correctly.

Many directors either underclaim or claim incorrectly, both of which can be costly.

Need a Local UK Accountant to Review Your Expenses?

If you run a UK limited company and want to ensure your expenses and Corporation Tax are fully HMRC-compliant and tax-efficient, speak to Ascend Accounts Ltd.

 UK-based support
 Specialist limited company advice
 Clear, practical guidance

 Contact Ascend Accounts Ltd today to stop overpaying Corporation Tax.