Is free fuel from work worth it?
Free fuel for personal trips is taxed however few miles you drive. See whether it pays.
Your answer
Enter the car's CO2, your miles and your salary to see the answer.
About this calculator
For company car drivers whose employer offers a fuel card for personal miles.
What happens to your answers
We don’t keep them. Your answers go to our server to do the sums and aren’t stored or logged. If you copy a link to your answers, they’re in the link itself, so only share it with people you trust.
How it’s worked out
Free fuel is taxed as if it were pay: £29,200 times the same share used for the car itself. That's a fixed amount, so it only pays off if you drive a lot of personal miles.
Worked example
Free fuel isn't worth it: you'd pay £3,450 a year in tax for about £750 of personal fuel. Paying for your own saves £2,700.
2026/27 tax year · petrol · salary £50,000
| Free fuel taxed as pay: £29,200 × 30% (120g/km) | £8,760 |
|---|---|
| Tax you'd pay on it | £3,450 |
| 5,000 personal miles at 15p a mile | £750 |
Worked out using HMRC's published rates for the 2026/27 tax year (6 April 2026 to 5 April 2027), on a yearly basis.
Questions people ask
Can I keep the fuel card for work trips only?
Yes. If you pay back the full cost of all personal fuel by the deadline, there's no fuel charge at all.
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