The Short Answer
Yes, if you're driving for business, fuel (or a mileage allowance instead) is an allowable expense.
Dan drives to three different sites in a day for work, that fuel's allowable. Him nipping to the supermarket on the way home for his dinner, that bit isn't.
The key word is "business." Fuel used getting to and from jobs, between sites, or picking up materials counts. Fuel used for anything personal doesn't, even if it happens in the same tank on the same day.
Two Ways to Claim It
There are two different methods, and you pick one, not both:
- Mileage rate — claim a flat rate per business mile for cars and vans (per tax year - 55p per mile for the first 10,000 miles, 25p after that)*
- Actual costs — claim the real cost of fuel, plus a share of servicing, insurance, and other running costs, based on the split between business and personal use
Most sole traders find the mileage rate simpler, since it's just a log of miles rather than keeping every single fuel receipt and working out a business-use percentage.
*rates from 06/04/26. Rates per tax year prior were 45p per mile for the first 10,000 miles, 25p after that.
What If You Use the Vehicle for Both?
Mia uses her van for jobs during the week, and for the school run and shopping at the weekend. She can only claim for the business miles, the personal trips don't count. Even though it's the same van and the same tank.
This is exactly why keeping a mileage log matters. Without one, it's very hard to prove what was business and what wasn't if HMRC ever asks.
What Counts as a Business Journey?
- Driving to a client's site or job
- Travelling between different sites in the same day
- Trips to collect materials or supplies
- Travel to a training course related to the business
Your regular commute from home to a fixed, permanent place of work doesn't count, but travelling to different sites each day (like most builders do) does.
What About VAT?
If you're VAT registered and using the actual costs method, you can reclaim VAT on the fuel itself, based on the business-use portion. If you're using the mileage rate, you can claim VAT using HMRC Advisory Fuel Rates.
Keep It Simple: Log Your Miles
Whichever method you use, keep a simple log: date, where you went, why, and how many miles. A notes app or a simple spreadsheet works fine. It doesn't need to be fancy, it just needs to exist.
Your Satnav Isn't Watching (But Keep the Log Anyway)
No, HMRC isn't tracking your route to the chippy. But if they ever ask about your mileage claim, "I'm pretty sure it was mostly work" won't cut it. Only a proper log will.