HMRC Mileage Logbook Rules: Recordkeeping Checklist for 2026

A compliant UK mileage log has nothing to do with which app you use. What matters is whether your records are clear, complete, and retrievable months or years after the journeys took place.

HMRC does not prescribe a specific format for mileage logs. There is no official template you must follow. But they do expect records that are accurate, kept contemporaneously (or as close to it as possible), and retained for long enough to cover any enquiry window.

This checklist covers what to record, how long to keep it, and what HMRC actually looks for if they open an enquiry.

Core fields for each journey

At minimum, every business journey entry should include:

• Date — the actual date of travel, not the date you entered it.
• Start location — enough context to identify the origin (e.g. “Home, Bristol” or “Main office, Reading”).
• End location — the destination with similar specificity.
• Business purpose — a clear, specific reason. “Client meeting with Barker & Co re: Q3 accounts” is strong. “Work” is not.
• Miles driven — the distance for that journey, measured or calculated.

Optional but useful extras:

• Vehicle used (essential if you drive more than one).
• Client or project reference.
• Whether the journey was to a temporary workplace.
• Passengers carried for business (relevant for the 5p per mile supplement).

Keep commuting separate from business travel

Ordinary commuting — travel between your home and a permanent workplace — is not claimable as business mileage. Your log must make this distinction obvious without anyone needing to interpret or guess.

Practical approach:

• Tag regular commute patterns once, so they are automatically excluded from business totals.
• Review edge-case journeys manually each week — trips that start or end at your home but go to a temporary workplace may qualify.
• Avoid vague labels. “Meeting” with no location tells HMRC nothing. “Project review at temporary site, Cheltenham” tells them everything they need.

HMRC’s employment income manual on travel expenses sets out the permanent vs temporary workplace rules in full.

Weekly quality checks

Spend five minutes each week on your log:

• Clear any uncategorised entries.
• Fix route anomalies (GPS drift, duplicate trips).
• Add purpose labels for ambiguous journeys while the context is fresh.

Small weekly updates prevent large-scale repair work at year-end. After three or four weeks, you will not remember whether a Wednesday trip to Swindon was business or personal.

Monthly evidence archiving

At each month-end:

1. Export a summary report (PDF) — total business miles, total personal miles, cumulative annual business miles.
2. Export raw journey data (CSV) — every trip with all fields.
3. Store both in a month-specific folder.

Folder structure example:

• mileage/2026/01/
• mileage/2026/02/
• mileage/2026/03/

Even if your tracking app stores everything in the cloud, keep local exports. Cloud services change, accounts get closed, and data formats shift. A set of monthly PDF and CSV files is the simplest insurance against losing access.

The 5-year retention period

HMRC requires you to keep business records for at least 5 years after the 31 January Self Assessment deadline for the relevant tax year.

For the 2025/26 tax year (filed by 31 January 2027), that means retaining records until at least 31 January 2032.

If HMRC opens an enquiry, they can go back further in cases of deliberate error, but five years is the standard retention window for most self-employed people. The GOV.UK record-keeping page confirms the requirements.

Destroying records early is one of the easiest mistakes to make — and one of the hardest to fix once HMRC asks for them.

Digital vs paper logs

HMRC accepts both digital and paper mileage logs. There is no legal requirement to use software. A paper notebook with consistent entries will satisfy an enquiry just as well as an app, provided the information is complete.

That said, digital logs have practical advantages:

• Automatic GPS capture reduces manual entry errors.
• Calculations (cumulative miles, threshold splits) are handled for you.
• Exports are faster when your accountant or HMRC asks for specific months.
• Backup and retrieval are simpler over a five-year retention window.

Paper logs work, but they rely on discipline. Missed entries are harder to reconstruct, totals must be calculated by hand, and physical notebooks can be lost.

Making Tax Digital (MTD) and mileage records

From April 2026, self-employed individuals and landlords with income over £50,000 must comply with Making Tax Digital for Income Tax Self Assessment (MTD for ITSA). The threshold drops to £30,000 from April 2027.

Under MTD, you must keep digital records and submit quarterly updates to HMRC using compatible software. Your mileage log does not need to be inside your MTD software, but it does need to feed into it. If you claim simplified expenses (flat-rate mileage), your quarterly update must include the mileage-based expense figure.

What this means in practice:

• If you already use a digital mileage tracker, you are largely covered — just make sure your exports can be imported into your MTD-compatible accounting software.
• If you currently use paper logs, you will need a way to digitise the mileage figures for quarterly reporting.
• HMRC’s MTD for ITSA guidance lists compatible software.

MTD does not change what you record in your mileage log. It changes how frequently and in what format you report it.

What HMRC checks during an enquiry

If HMRC opens an enquiry into your mileage claims, they are looking for patterns that suggest the records are inaccurate or inflated. Common areas of focus:

• Consistency — Do your logs cover the full year, or are there gaps? Months with no entries followed by months with high claims look suspicious.
• Specificity — Generic purpose descriptions (“business,” “client,” “meeting”) without locations or names raise questions.
• Commuting treatment — Regular journeys to the same address every day look like commuting, regardless of how you label them.
• Threshold accuracy — Did you correctly split mileage at the 10,000-mile mark, or did you apply 45p to everything?
• Supporting evidence — Can you produce invoices, calendar entries, or correspondence that corroborate the journeys? HMRC does not expect proof for every single trip, but they expect some.
• Round numbers — A log where every journey is exactly 10 or 20 miles looks fabricated.

An enquiry does not mean HMRC thinks you are dishonest. In many cases, it is a random compliance check. But having clear, well-organised records turns a stressful process into a straightforward one.

Typical recordkeeping mistakes

Backfilling from memory

Reconstructing three months of journeys from memory produces vague entries and inaccurate distances. Contemporaneous recording — ideally on the day of travel — is far stronger.

Blended multi-stop journeys

If business and personal legs are mixed in one journey, split them into separate records. Home → Client → Gym → Office should be at least two entries, with the personal leg excluded.

Missing threshold awareness

If your annual business mileage crosses 10,000 miles, both your log quality and calculation precision matter. An error in the threshold split compounds across every mile above 10,000.

Inconsistent vehicle recording

If you use more than one vehicle for business travel — say a car and a motorcycle — each vehicle’s mileage must be tracked separately. AMAP rates differ by vehicle type (45p/25p for cars, 24p for motorcycles, 20p for bicycles), and the 10,000-mile threshold applies per person, not per vehicle. Failing to note which vehicle you used on a given journey makes it impossible to calculate your claim correctly at year-end.

How long does an HMRC enquiry take?

If HMRC does open an enquiry, the timeline depends on how quickly you can produce your records. For taxpayers with well-organised monthly exports, the process is often resolved within a few weeks of correspondence. If records are scattered, incomplete, or need to be reconstructed, the enquiry can stretch over several months.

HMRC can open an enquiry up to 12 months after the filing deadline for a standard return, or longer if they suspect carelessness or deliberate error. Having five years of clean, accessible records means you are covered regardless of when the enquiry lands.

Build a repeatable workflow

Combine these linked guides for a complete UK mileage process:

• HMRC Mileage Rates 2026: Practical AMAP Guide for UK Claims — rates, thresholds, and MAR claims.
• Mileage Claim HMRC: Self-Employed Workflow That Survives Review — weekly and monthly workflow for self-employed filers.

Together with this recordkeeping checklist, these three guides cover rates, claims process, and evidence architecture.

Pre-filing self-audit

Before you submit your Self Assessment, confirm:

• Every business month has archived exports (summary + raw data).
• Journey purposes are specific enough that a stranger could understand them.
• Commuting treatment is consistent across the full year.
• Annual totals reconcile with monthly files.
• The 10,000-mile threshold split is correct.
• Records are stored somewhere they will survive for five years.

A high-quality logbook lowers filing risk and cuts the time you spend explaining records later — whether to your accountant or to HMRC.

MileTrack captures journeys automatically, classifies them as business, commute, or private, and exports claim-ready reports with all the fields HMRC expects. See the current UK product page at miletrack.app/en-gb.

Tax note: this article is educational and does not replace advice from a qualified UK tax professional.