If your company pays for all your fuel used by your company car and you do not identify and pay back the personal mileage element, then there is a taxable fuel benefit as well as your car benefit.
Calculation Example
The car fuel benefit is based on a set figure £27,800 for 2024/25 (2023/24 £27,800) x benefit in kind percentage for your company car. To calculate the benefit in kind percentage for your company car in the schedule below:
Petrol powered and hybrid powered cars for the tax year 2024 to 2025
| CO2 emissions (grams per km) | Electric mileage range | NEDC % | WLTP % |
|---|---|---|---|
| 0 | N/A | 2 | 2 |
| 1 to 50 | 130 and above | 2 | 2 |
| 1 to 50 | 70 to 129 | 5 | 5 |
| 1 to 50 | 40 to 69 | 8 | 8 |
| 1 to 50 | 30 to 39 | 12 | 12 |
| 1 to 50 | less than 30 | 14 | 14 |
| 51 to 54 | 15 | 15 | |
| 55 to 59 | 16 | 16 | |
| 60 to 64 | 17 | 17 | |
| 65 to 69 | 18 | 18 | |
| 70 to 74 | 19 | 19 | |
| 75 to 79 | 20 | 20 | |
| 80 to 84 | 21 | 21 | |
| 85 to 89 | 22 | 22 | |
| 90 to 94 | 23 | 23 | |
| 95 to 99 | 24 | 24 | |
| 100 to 104 | 25 | 25 | |
| 105 to 109 | 26 | 26 | |
| 110 to 114 | 27 | 27 | |
| 115 to 119 | 28 | 28 | |
| 120 to 124 | 29 | 29 | |
| 125 to 129 | 30 | 30 | |
| 130 to 134 | 31 | 31 | |
| 135 to 139 | 32 | 32 | |
| 140 to 144 | 33 | 33 | |
| 145 to 149 | 34 | 34 | |
| 150 to 154 | 35 | 35 | |
| 155 to 159 | 36 | 36 | |
| 160 to 164 | 37 | 37 | |
| 165 to 169 | 37 | 37 | |
| 170 and above | 37 | 37 |
The exact CO2 figure is always rounded down to the nearest 5 grams per km — except where noted in the table. For example, CO2 emissions of 168 grams per km are treated as 165.
For each tax year add 4% for diesel cars up to a maximum of 37%.
So in this example, the car fuel benefit is £27,800 x 37% = £10,286 taxable benefit.
Therefore the director will pay personal tax on this amount, if he is higher rate tax payer, this will be £10,286 x 40% = £4,114.40.
Best practice is for the director to ONLY claim his business mileage if he wishes to avoid this taxable benefit.