Claiming Business Mileage In Your Self Assessment Return

By Author: SATR accountants
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For self-employed individuals and small business owners in the UK, claiming business mileage can provide a significant tax relief. If you frequently use your vehicle for business-related tasks—such as visiting clients, making deliveries, or attending meetings outside your regular workspace—then you may be eligible to deduct mileage costs from your taxable profits. These claims must be submitted accurately through your Self Assessment Tax Return.

Understanding the rules surrounding mileage deductions and how to report them can help reduce your overall tax liability while staying compliant with HMRC.

What Is Business Mileage?
Business mileage refers to the distance you travel exclusively for work-related purposes using your personal or company vehicle. This excludes ordinary commuting to a permanent place of work, which is considered private use.

Examples of valid business journeys include:

Travelling to temporary work locations

Client meetings at off-site locations

Driving to training events or conferences

Transporting ...
... goods or equipment related to your business

You must keep clear and accurate records to back up any mileage claim submitted in your Self Assessment Tax Return.

Who Can Claim Business Mileage?
Anyone who files a Self Assessment Tax Return and uses a vehicle for legitimate business reasons may claim mileage expenses. This includes:

Sole traders

Freelancers

Contractors

Limited company directors (in some cases)

If you're both employed and self-employed, you must carefully differentiate between employer-paid travel and self-employment travel expenses when you file tax return online UK.

Two Methods to Claim Business Mileage
1. Simplified Expenses (Flat Rate Method)
HMRC allows self-employed individuals to use fixed mileage rates under the simplified expenses scheme. These are:

45p per mile for the first 10,000 business miles in a tax year

25p per mile for any miles above 10,000

24p per mile for motorcycles

This method is straightforward and doesn’t require tracking individual vehicle expenses such as fuel, insurance, or repairs.

2. Actual Vehicle Costs Method
This method involves calculating the percentage of business use and applying it to total vehicle expenses. You must keep receipts and documents for:

Fuel

Repairs and servicing

MOT and insurance

Road tax

Depreciation (if applicable)

This method is more complex but may be suitable for high-cost vehicles or if your business mileage is low but running costs are high. Whichever method you choose must be used consistently for the life of the vehicle.

More about both methods can be found on Wikipedia’s page about UK Taxation.

Record-Keeping Requirements
Accurate records are essential when claiming mileage. HMRC may request to see your log at any time. Each record should include:

Date of journey

Starting point and destination

Purpose of journey

Number of miles travelled

Using a mileage logbook, spreadsheet, or mobile app can make this process easier. Apps such as MileIQ or Everlance automatically track and categorise your trips, simplifying submission through online tax filing services.

How to Enter Mileage in Your Self Assessment Tax Return
When using the simplified method, declare the total mileage cost in the self-employment section (SA103) under “business expenses” while submitting your Self Assessment Tax Return.

Steps to follow when you file tax return online UK:

Log in to your Government Gateway account.

Navigate to the “Self-employment” section.

Enter your income (gross turnover).

Enter allowable business expenses, including mileage, in the appropriate fields.

Use the summary page to double-check all figures.

Submit your return and keep a digital or physical copy for your records.

For guidance, visit the official HMRC Self Assessment page.

Common Mistakes to Avoid
1. Claiming Commuting as Business Travel
Travelling between home and your regular place of business is not eligible for mileage claims. This is considered a personal expense.

2. Poor Record Keeping
Vague or missing details could lead to HMRC rejecting your claim. Always log each journey in real time to avoid errors.

3. Mixing Flat Rate and Actual Costs
You cannot switch between simplified and actual costs once you've chosen a method for a vehicle. Stick with one until you replace the vehicle.

4. Overestimating Mileage
Exaggerating mileage is a red flag to HMRC. Be precise and truthful—random audits can happen.

Mileage for Electric Vehicles and Hybrids
Even if you use an electric or hybrid vehicle, you can still claim mileage at the same rates provided by HMRC. The fuel type does not affect eligibility when using the simplified method.

Electric vehicle owners may also benefit from lower running costs and additional environmental tax reliefs. However, actual cost calculations may differ if you’re using electricity bills instead of fuel receipts under the actual cost method.

When to Seek Help
If you're uncertain which method benefits you most or how to properly allocate business use, consider using HMRC Self Assessment Help. You can also explore digital online tax filing services that simplify the input process with built-in guidance and automatic calculations.

Final Thoughts
Claiming business mileage accurately on your Self Assessment Tax Return is a simple yet powerful way to reduce your tax bill legally. Whether you’re a consultant on the road or a delivery-based entrepreneur, proper mileage tracking can translate into hundreds—or even thousands—of pounds in tax savings.

Make sure to file tax return online UK with full accuracy, supported by solid record keeping. For greater efficiency, leverage online tax filing services or consult HMRC directly through their official support portal.

Maintaining diligence in this area not only maximises financial benefit but also ensures peace of mind during tax season.