MilometryA tax year end checklist for anyone who drives for work
What to do in the fortnight before 5 April, and the three things that are much harder to fix afterwards. A checklist for anyone who drives for work.
Algemene informatie, geen advies. Geschreven als algemene informatie en voor zover wij weten juist op 27 september 2026. Belastingregels veranderen, en hoe ze uitpakken hangt af van je eigen situatie. Dit is geen belasting-, juridisch of financieel advies: vraag een accountant, een belastingadviseur of de Belastingdienst voordat je erop vertrouwt.
The UK tax year ends on 5 April. Nothing dramatic happens on the day, but a few things get considerably harder once it has passed. Here is the short list.
1. Sort anything still unclassified
An unclassified journey is in no total. If you have a backlog of trips you never got round to marking business or personal, those miles are missing from your total.
Do it now while you can still remember what a Tuesday in November was for. In six months you will be guessing, and a guessed log is a weak log.
2. Check your business mileage against the 10,000 line
For employees, the approved rate for cars and vans drops from 55p to 25p once you pass 10,000 business miles in the tax year (counted per employment), and the counter resets on 6 April. The 55p applies to journeys from 6 April 2026; the rate was 45p before that. If you are self-employed and use simplified expenses, the same rates apply, but the 10,000 is counted over your accounting period.
Check where you are against 10,000 so each trip is banded correctly. The count restarts on 6 April.
3. Reconcile your odometer
This is the one people skip and later regret. Compare what your odometer says against what your log accounts for. If the car has covered 14,000 miles and your journeys add up to 11,000, then 3,000 miles went unrecorded, and unrecorded business miles cannot be claimed.
You will not recover all of it, but a gap between two known dates is a far better prompt for your memory than a blank year. Milometry does this comparison for you from your fill-up odometer readings and flags stretches where the two disagree.
4. Collect the out-of-pocket costs
Parking, tolls, congestion and clean-air charges on business journeys sit outside the mileage rate: an employer can reimburse them, and the self-employed can deduct them on top of simplified mileage. The mileage rate covers running the vehicle, not what you paid to leave it somewhere.
Receipts are easier to find in April than in January. If you photograph them onto the journey as you go, this step is already done.
5. Export before you need it
Produce the CSV and the claim PDF for the year while everything is fresh, and put them somewhere that is not only your phone. If you file in January, the version of events you want is the one you assembled in April.
6. Check how long to keep it
Employees who file a tax return should keep records for at least 22 months after the end of the tax year. The self-employed should keep them for at least 5 years after the 31 January filing deadline. If you might backdate a claim, keep the records for every year you claim. Deleting last year's log to tidy up is a bad trade.
The checklist in one table
| # | Task | Why it is harder later | Time |
|---|---|---|---|
| 1 | Sort anything unclassified | Memory fades; guesses are weak evidence | 10 min |
| 2 | Check where you are against 10,000 miles | The counter resets on 6 April | 1 min |
| 3 | Reconcile the odometer against your log | A year-old gap is unrecoverable | 5 min |
| 4 | Collect parking, tolls and charges | Receipts vanish | 15 min |
| 5 | Export the CSV and claim PDF | You will file in January from April's data | 2 min |
| 6 | Check retention periods | Deleting last year to tidy up is costly | n/a |
Key dates
| Date | What happens |
|---|---|
| 5 April | Tax year ends |
| 6 April | New tax year begins; employees' 10,000-mile counter resets |
| 31 October | Paper Self Assessment deadline |
| 31 January | Online filing and payment deadline for the year ended the previous 5 April |
| 4 years back | Mileage Allowance Relief can be claimed for the current tax year and the previous four |
Sources
- How long to keep your records: employees and others filing a tax return (HMRC)
- How long to keep your records if you're self-employed (HMRC)
- Travel, mileage and fuel rates and allowances (HMRC)
- Increasing mileage rates (HM Treasury and HMRC policy paper)
- Simplified expenses: vehicles (HMRC)
- Claim tax relief for your job expenses: vehicles you use for work (HMRC)
- Expenses if you're self-employed: car, van and travel expenses (HMRC)
General information for UK drivers, not tax advice.
