MilometryHow to keep a mileage log that stands up
What HMRC expects a mileage record to contain, how long to keep it, and why the spreadsheet you fill in every April is the weakest version of it.
Allgemeine Information, keine Beratung. Als allgemeine Information verfasst und nach unserem Wissen korrekt am 27. September 2026. Steuerregeln ändern sich, und wie sie gelten, hängt von deinen Umständen ab. Dies ist keine Steuer-, Rechts- oder Finanzberatung: Frag eine Steuerberaterin, einen Steuerberater oder das Finanzamt, bevor du dich darauf verlässt.
A mileage claim is only as good as the record behind it. If someone asks you to justify 8,400 business miles two years after the fact, you want a log that answers the question rather than a number you once believed.
What a record should contain
For every business journey:
- The date it happened
- Where you started and where you finished
- Why it was business, in enough words to jog a memory
- How far you went
- Which vehicle you used, if you have more than one
Add a running total for the tax year and you can show the banding is right: for cars and vans, 55p a mile for the first 10,000 business miles and 25p after (for journeys from 6 April 2026). Reconstructed logs often get this wrong.
How long to keep it
- Employees who file a tax return: at least 22 months after the end of the tax year the claim relates to.
- Self-employed: at least 5 years after the 31 January filing deadline for that tax year.
If you might backdate a claim, keep the records for every year you claim.
Keep the record in a form you can still open. A note on a phone you no longer own is not a record.
Why the April spreadsheet is the weak version
Three things go wrong when you write it all up at the end of the year.
Memory. You remember the big trips and forget the twenty-mile round trip to a supplier in October. Those are the miles you paid for and never claimed.
Distance. Postcode-to-postcode estimates are not the same as the route you drove. Sometimes that is in your favour, sometimes it is not, and either way it is not evidence.
Banding. Fill in the mileage in one lump and there is no running total showing when you crossed 10,000, so you cannot check that what you were paid through the year was banded correctly.
The habit that fixes it
Record as you go, and sort promptly. Anything that captures the drive at the time (an app, a notebook in the glovebox, a note dictated at the traffic lights) beats a perfect spreadsheet built from memory.
If you use Milometry, this is the whole design: the journey is recorded while it happens, and the only question left is business or personal. It bands each trip against your running total for the tax year, keeps a per-trip and per-month record, and exports the lot as a PDF or CSV that reads like something you could hand to an accountant, because that is what it is for.
A quick self-test
Pick a random week from three months ago. Can you say, without guessing:
- Which drives you made for work?
- Where each one started and ended?
- How far each one was?
- Why it was business?
If the answer is no, your log is not a log yet. That is entirely fixable, and the fix takes about ten seconds a day.
What a record must contain
| Field | Required? | Example | What it proves |
|---|---|---|---|
| Date | Yes | 14 Aug 2026 | Ties to calendar, invoices, fuel receipts |
| Start location | Yes | Home | Establishes commuting or not |
| Destination | Yes | Acme Ltd, Harrogate | The workplace, not just a town |
| Purpose | Yes | Site survey | The business character |
| Distance | Yes | 18.4 mi | The claim itself |
| Vehicle | If more than one | Van, AB26 CDE | Keeps totals apart |
| Route | Helpful | Recorded | Answers "why so far?" |
| Running total | Helpful | 4,210 mi YTD | Gets the banding right |
How long to keep it
| If you are | Keep records until |
|---|---|
| Employed and filing a tax return | At least 22 months after the end of the tax year |
| Self-employed | At least 5 years after the 31 January filing deadline |
| Running a limited company | 6 years from the end of the company financial year the records relate to |
Strong record versus weak record
| Weak | Strong |
|---|---|
| "August: 340 business miles" | 22 individual journeys totalling 341.6 miles |
| Round numbers throughout | Distances that are obviously measured |
| Written up in April from memory | Recorded on the day |
| No purpose recorded | Client or job named on each trip |
| Commuting included | Home-to-workplace excluded and visibly so |
| One total across two vehicles | Each vehicle separately |
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)
- 490: Tax and National Insurance contributions for employee travel (HMRC)
- Expenses if you're self-employed: car, van and travel expenses (HMRC)
- Running a limited company: company and accounting records (HMRC and Companies House)
- Increasing mileage rates (HM Treasury and HMRC policy paper)
General information for UK drivers, not tax advice.
