How to Keep a Mileage Log That HMRC Will Accept

Published 12th January 2026

I'll be straight with you: if you're claiming mileage and don't have a proper log, you're asking for trouble. HMRC expects records. Good records. Not a vague list scribbled on the back of a receipt in January. A proper mileage log is your safety net if they ever come asking questions -- and it makes your tax return about ten times easier to complete.

Here's exactly what you need to record, the best way to do it, and what happens if HMRC decides to take a closer look.

What HMRC Requires You to Record

There's no set format -- HMRC doesn't hand you a template. But they do expect certain details for every single business journey. Miss any of these and your log has holes:

Date: The actual date. "Sometime in March" won't fly. Write it down the same day.
Start and finish: Where you left from and where you went. Include addresses or at minimum the town/city plus the client or venue name.
Why: A brief business reason. "Client meeting with Smith & Co" or "site visit, Birmingham project." Just a few words that prove it was for work.
Miles: The number of business miles. Direct route only -- don't include the detour via Tesco.
Running total: A cumulative count for the tax year. You need this to know when you cross the 10,000-mile threshold and the rate drops from 45p to 25p.

Example Mileage Log Entry

Date	From	To	Purpose	Miles	Cumulative
12 Jan 2026	Home, Leeds	ABC Ltd, Manchester	Client project review meeting	45	45
12 Jan 2026	ABC Ltd, Manchester	Home, Leeds	Return from client meeting	45	90
15 Jan 2026	Office, Leeds	XYZ Corp, Sheffield	New client pitch presentation	38	128
15 Jan 2026	XYZ Corp, Sheffield	Office, Leeds	Return to office	38	166

Apps vs Paper Logs: Which Is Better?

HMRC doesn't care whether your log is digital or paper. They care that it exists, it's detailed, and it was filled in at the time (not cobbled together the night before your tax return is due). Pick whichever method you'll actually stick with.

Paper Mileage Logs

Old school but effective. A notebook in the glovebox, filled in after every trip. No app to crash, no battery to die, no subscription fee. The downside? You'll forget to fill it in. Or leave it in the car wash. Or your dog will eat it. If you go paper, keep it in the car and write in it before you turn the ignition off. Make it a habit or it won't happen.

Spreadsheet

My personal favourite. Set up a Google Sheet with formulas for cumulative miles and claim totals, and update it from your phone after each trip. Takes 30 seconds. The big advantage of Google Sheets? It automatically timestamps when each row was added or modified. If HMRC asks whether you filled it in at the time or in a panic at year end, the metadata backs you up.

Dedicated Mileage Tracking Apps

If you want something purpose-built, there are several decent options in the UK:

MileIQ: Automatically detects when you are driving and logs the journey. You simply swipe to classify each trip as business or personal. Subscription-based, but very convenient.
Driversnote: Similar automatic tracking with a free tier. Generates HMRC-compliant reports.
Tripcatcher: UK-focused app designed specifically for HMRC mileage claims. Allows manual entry or GPS tracking and calculates your claim using the correct rates.
QuickBooks Self-Employed: Includes mileage tracking as part of a broader accounting package, useful if you are self-employed.

The big selling point of apps is GPS tracking -- it's impossible to forget a journey because the app logs it automatically. The downsides? Subscription costs, battery drain, and the slightly creepy feeling of being tracked everywhere you go. You also need to correctly classify each trip as business or personal, which still requires some effort.

The golden rule: Consistency matters more than the method. HMRC will happily accept a scruffy notebook with daily entries over a beautifully formatted spreadsheet that was clearly filled in on January 30th. Record your trips daily. Make it a habit like locking the car.

How Long Must You Keep Your Records?

Don't bin your records too soon. HMRC has specific retention periods:

Employees: Keep records for at least 22 months after the end of the tax year to which they relate. For example, records for the 2025/26 tax year (ending 5 April 2026) should be kept until at least 31 January 2028.
Self-employed: Keep records for at least 5 years after the 31 January Self Assessment deadline. For the 2025/26 tax year, this means keeping records until at least 31 January 2032.

If HMRC opens an enquiry, they might ask for records going back further. My advice? Keep digital backups forever. Storage is essentially free, and having the records available if anyone ever asks is priceless.

What Happens During an HMRC Audit?

It's not as scary as it sounds, but you need to be prepared. Here's the typical process:

Information request: HMRC will write to you (or your accountant) requesting evidence to support your mileage claims. This will include your mileage log, details of the journeys, and how you calculated the distances.
Review of records: HMRC will check that your log is detailed, consistent, and credible. They may cross-reference your claimed journeys with other information such as your calendar, client records, or email correspondence.
Distance verification: HMRC may use mapping tools to check that the distances you have claimed are reasonable for the routes involved. Consistently claiming significantly more miles than the direct route would raise questions.
Business purpose verification: HMRC will check that each claimed journey had a genuine business purpose and was not ordinary commuting or a personal trip.

No records? Big problem. Without a mileage log, HMRC will likely disallow some or all of your claim. You've got no evidence. They might accept a reasonable estimate backed up by diary entries or client meeting notes, but that's entirely at their discretion. Don't gamble on it. Keep the log.

Tips for Bulletproof Mileage Records

Record journeys on the day they happen. Do not rely on memory at the end of the week or month.
Use consistent sources for distances. Google Maps or similar tools provide reliable route distances. If HMRC queries your figures, you can point to the same source.
Keep supporting evidence. Calendar entries, meeting notes, emails confirming appointments, and client invoices all corroborate that the journey took place.
Separate business and personal miles clearly. If a single trip includes both business and personal elements, only claim the business portion.
Back up your records. Whether digital or paper, ensure you have a backup. Photograph paper logs or scan them regularly.
Review your log monthly. A quick monthly review helps catch any missing entries or errors while you can still correct them.

A decent mileage log takes two minutes a day. That's it. Two minutes for peace of mind and a bulletproof claim. Start today -- not next month, not next tax year. Today.

Use our mileage claim calculator to quickly calculate the value of your recorded business miles.