Mileage records and HMRC: what a compliant business mileage log looks like

By the Smart Strix team · Updated 15 July 2026

Mileage is one of the most commonly claimed business expenses and one of the most casually recorded — a combination HMRC enquiries are built for.

In short: gov.uk guidance expects businesses to keep records supporting the expenses they claim and the payments they make to employees, and for mileage that means a contemporaneous log of each business journey — date, start and end points, purpose and miles. HMRC publishes approved mileage rates (AMAP) for employees using their own vehicles; the figures change over time, so always take the current rates from gov.uk. This guide from Smart Strix, the UK-first platform for 2–50 vehicle fleets, explains what a compliant log contains. It is not tax advice — speak to an accountant about your specific position.

What does HMRC expect a mileage record to show?

Gov.uk record-keeping guidance requires businesses to hold evidence backing up their tax returns and expense payments, and for mileage claims the accepted standard is a journey-level log. Each entry should capture:

Date of the journey
Start and end locations — postcodes or recognisable addresses, not "out and about"
Business purpose — client visited, delivery made, site attended
Miles travelled, with round trips shown as such
Vehicle and driver, where more than one of either exists

Two qualities matter as much as the fields. First, contemporaneity: a log built at the time beats one reconstructed at year-end from diary archaeology, and reconstructed logs are exactly what enquiries pull apart. Second, the business–private split: only business miles qualify, and ordinary commuting between home and a regular workplace generally does not count as business travel under gov.uk rules — a distinction worth confirming with an accountant for your circumstances, since "regular workplace" has nuances.

How do HMRC approved mileage rates work?

Where employees use their own vehicles for business journeys, HMRC's approved mileage allowance payments (AMAP) scheme lets employers reimburse up to published per-mile rates without the payment being taxable. Points to understand — with the standing caveat that rates and rules should be taken from gov.uk at the time you use them:

Rates differ by vehicle type (cars and vans, motorcycles, bicycles) and, for cars and vans, drop after a threshold of business miles in the tax year.
Paying up to the approved rate: no tax or reporting on the payment. Paying above it: the excess is generally taxable. Paying below it: employees may be able to claim tax relief on the shortfall.
The rates are designed to cover the whole cost of using the private vehicle — fuel, wear, insurance, depreciation — which is why grey fleet mileage at scale often costs more than a pool van; our grey fleet guide covers the safety side of those journeys.
Company-owned vehicles work differently — separate advisory fuel rates exist for company cars, and fuel for company vans has its own treatment. This is squarely accountant territory.

We deliberately quote no figures here: mileage rates are revised, and a stale number is worse than none. Search "HMRC mileage rates" on gov.uk for the current table before setting your reimbursement policy.

What does a compliant mileage log look like in practice?

Date	From → To	Purpose	Miles
03/07	Depot (NW10) → Client site (RG1) → Depot	Equipment delivery, job #1042	86
04/07	Home (HA4) → Supplier (UB2) → Depot	Parts collection for VOR van	19

Notice what makes these entries defensible: specific postcodes, a purpose that ties to a job reference, and a mileage figure that can be sanity-checked against a route planner. A claim of round-number miles ("50") every day between vague locations invites questions; a claim of 86 miles to a named client on a numbered job answers them before they are asked. Periodic odometer readings — say, monthly — add a cross-check that total claimed miles fit inside total miles driven.

How long should mileage records be kept?

Gov.uk sets minimum retention periods for business records — broadly, several years after the relevant tax year, with different spans for companies, the self-employed and PAYE records. Rather than memorise the matrix, adopt a simple fleet rule: keep mileage logs and the expense records they support for at least six years, digitally, and you will comfortably cover the common cases. Confirm the precise requirement for your entity type with your accountant. Digital storage matters practically too — a five-year-old claim is only useful if you can actually retrieve it.

What are the common mileage record mistakes?

Reconstructing at year-end: the log becomes an estimate wearing a spreadsheet's clothes.
Claiming commutes: home-to-regular-workplace travel generally is not business mileage; misclassifying it is the classic enquiry finding.
Round numbers everywhere: genuine journeys produce irregular figures; uniform ones signal estimation.
No purpose recorded: miles without a business reason attached are unverifiable by definition.
Mixing vehicles: when a driver uses both a company van and their own car, the logs must separate them — the tax treatment differs.
No cross-checks: odometer photos at fuel fills and periodic readings anchor the log to physical reality.

For fleets running their own vans, much of the raw material already exists in operational records: jobs with addresses and timestamps, fuel logs with odometer photos. Smart Strix captures those as part of daily work — job history in dispatch, odometer and receipt photos in fuel logs — giving your accountant evidence rather than estimates. The tax rules themselves live on gov.uk and change; take current rates and retention rules from there, and treat everything on this page as record-keeping practice, not tax advice.

Frequently asked questions

What details must a mileage log contain for HMRC?

Per journey: date, start and end locations, business purpose, and miles travelled — plus vehicle and driver where several exist. Gov.uk record-keeping guidance requires evidence supporting claims; a contemporaneous journey-level log is the accepted standard. Confirm specifics with an accountant.

What are the current HMRC mileage rates?

HMRC publishes approved mileage allowance payment (AMAP) rates by vehicle type, with a lower rate for cars and vans beyond an annual business-mile threshold. The figures are revised over time, so take them from gov.uk directly rather than from any guide, including this one.

Does commuting count as business mileage?

Ordinary commuting between home and a regular workplace generally does not qualify under gov.uk rules. Travel between workplaces, to customer sites and to temporary workplaces generally can. The boundaries have nuances — a question for your accountant, not a mileage app.

Can I estimate my business mileage instead of logging it?

Estimates are exactly what enquiries dismantle. A log kept at the time, with specific locations and purposes tied to jobs or clients, is both the compliance expectation and your protection. If history is missing, start logging properly today and take advice on the gap.

How long do mileage records need to be kept?

Gov.uk sets retention periods that vary by entity type, generally several years beyond the relevant tax year. Keeping mileage and expense records digitally for at least six years covers the common cases comfortably — confirm your exact obligation with an accountant.

Do company van drivers need mileage logs too?

Yes, though for different reasons — including evidencing that private use rules are met and supporting fuel treatment. Company-vehicle taxation differs from private-vehicle AMAP reimbursement, so keep the logs separate and ask an accountant how each should be handled.

Is GPS tracking data enough for HMRC mileage records?

Location history helps corroborate journeys but usually lacks the business purpose element on its own. The strong combination is operational records — jobs with addresses, timestamps and references — alongside mileage figures, which together show where, when and why.