Making Tax Digital (MTD) for Income Tax Self Assessment officially launches in April 2026, and mileage records sit right at the centre of the change. If you are self-employed or a landlord with income above £50,000, your days of keeping a paper mileage logbook and filing a single annual return are over. HMRC now expects digital records kept throughout the year and quarterly updates submitted through MTD-compatible software.
This guide covers everything you need to know about Making Tax Digital mileage requirements: what changes, who is affected first, what your digital mileage log must include, and how to get compliant before the deadline arrives.
What Is MTD for Income Tax Self Assessment?
MTD for Income Tax Self Assessment (MTD ITSA) replaces the traditional annual Self Assessment tax return for qualifying taxpayers. Instead of tallying everything once a year and filing by 31 January, you must:
- Keep digital records of all income and expenses from the start of each tax year
- Submit quarterly updates to HMRC summarising your income and expenses for each three-month period
- Submit a final declaration after the tax year ends, confirming your full-year figures
The quarterly updates are due by the 5th of the second month after each quarter ends. For the 2026/27 tax year, that means deadlines of 5 August, 5 November, 5 February, and 31 January (combined with the final declaration).
HMRC’s stated aim is to reduce errors in Self Assessment returns and give taxpayers a clearer, more up-to-date picture of their tax position throughout the year.
The Phased Rollout Schedule
MTD ITSA does not apply to everyone at once. The government has set a phased timetable based on gross income thresholds:
| Phase | Income threshold | Mandatory from |
|---|---|---|
| Phase 1 | Self-employment or property income over £50,000 | April 2026 |
| Phase 2 | Self-employment or property income over £30,000 | April 2027 |
| Phase 3 | Self-employment or property income over £20,000 | April 2028 |
The first year (2026/27) is also a soft-landing period. HMRC has confirmed that penalties for late quarterly updates will not be charged during the first year, giving taxpayers time to adjust to the new system. However, you are still required to keep digital records and submit updates — the soft landing applies to penalty enforcement, not to the obligation itself.
If your income falls below the current threshold, you can still sign up voluntarily. This is worth considering if your income is close to the boundary or you want to trial the process before it becomes mandatory.
How Making Tax Digital Affects Your Mileage Records
Under MTD, all business records must be kept in a digital format that allows electronic transfer. Mileage records are no exception. If you claim business mileage — whether through simplified expenses at 45p per mile or actual vehicle costs — the underlying journey records must be digital.
This has three practical consequences:
- Paper logbooks alone no longer qualify. A handwritten mileage diary cannot be electronically transferred to HMRC. You need a digital format: a spreadsheet, a mileage app, or records within your accounting software.
- Each journey must be recorded individually. HMRC requires journey-level granularity. Entering a single monthly mileage total is not sufficient. Each business trip needs its own entry with date, route, purpose, and distance.
- Records must be created contemporaneously. Digital records should be made at or near the time of the journey, not reconstructed from memory months later.
If you currently use a paper logbook, the simplest transition is switching to a mileage tracking app like Tripbook that automatically logs journeys via GPS and stores everything digitally.
The information HMRC expects in your mileage records has not changed under MTD — but the format has. Your digital mileage log must capture:
- Date of each business journey
- Start and end location (or a description of the route)
- Business purpose of the trip
- Miles driven for each journey
These fields are the same as those required under the existing HMRC business mileage record-keeping rules. The difference is that under MTD, the records must exist in a digital system from the point of recording. Transcribing paper notes into a spreadsheet at the end of the quarter does not meet the contemporaneous digital records standard.
Your quarterly update to HMRC will report the total vehicle expense for the period (for example, total business miles multiplied by the HMRC approved rate). You do not submit individual trip records each quarter, but HMRC can request them during an enquiry, and they must be available in digital form.
What Counts as MTD-Compatible Software?
To submit quarterly updates and your final declaration, you need MTD-compatible software that can communicate with HMRC’s systems via their API. For mileage specifically, there are several approaches:
Option 1: Mileage app feeding into accounting software. You track journeys in a dedicated mileage app and export the data into MTD-compatible accounting software that handles the quarterly submissions. Tripbook, for example, exports mileage records in CSV and PDF formats that slot directly into your accounting workflow.
Option 2: Accounting software with built-in mileage tracking. Some accounting packages include basic mileage logging features. These tend to be manual entry rather than GPS-based, which means more effort and greater risk of missed trips.
Option 3: Spreadsheet plus bridging software. You keep records in a spreadsheet and use HMRC-recognised bridging software to submit quarterly updates. This meets the minimum requirement but offers no automation.
For a detailed comparison of MTD-compatible mileage tools, see our guide to MTD-compatible mileage tracking apps.
Quarterly Updates: How Mileage Fits In
Each quarterly update summarises your income and allowable expenses for the period. Your mileage deduction — whether you use simplified expenses or actual costs — appears as a vehicle expense line within the update.
Here is how the quarterly cycle works for the 2026/27 tax year:
- Q1 (6 April – 5 July 2026): Submit mileage expense total by 5 August 2026
- Q2 (6 July – 5 October 2026): Submit by 5 November 2026
- Q3 (6 October – 5 January 2027): Submit by 5 February 2027
- Q4 (6 January – 5 April 2027): Submit by 31 January 2028 (with final declaration)
During the soft-landing period, HMRC will not charge penalties for late quarterly updates. But building the habit early means you avoid a backlog of unrecorded trips when the grace period ends.
If you use the HMRC approved mileage rate of 45p per mile, your quarterly mileage expense is simply your total business miles for the quarter multiplied by the applicable rate (45p for the first 10,000 miles in the tax year, 25p thereafter).
How to Get MTD-Ready for Mileage
Getting compliant is straightforward if you start now rather than waiting for the deadline:
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Switch to digital mileage tracking. If you are still using paper, move to an app or spreadsheet. Tripbook records every journey automatically via GPS, capturing the date, route, distance, and purpose — exactly what HMRC requires.
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Choose your accounting software. You need MTD-compatible software for quarterly submissions. Check that your chosen package can receive mileage data from your tracking tool.
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Set up your export workflow. Make sure you can move mileage totals from your tracking tool into your accounting software smoothly. Test this before April 2026 so there are no surprises.
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Brief your accountant. If you use an accountant, discuss the MTD transition. Many accountants are onboarding clients to MTD-compatible platforms well ahead of the deadline.
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Consider voluntary sign-up. You can join MTD ITSA voluntarily through HMRC’s online service. This lets you practise the quarterly submission process with no penalty risk during the soft-landing year.
MTD for Income Tax is no longer a distant policy announcement — it takes effect in April 2026. For anyone who drives for business, the core requirement is clear: your mileage records must be digital, journey-level, and available for quarterly reporting. Every trip you record digitally today is one fewer trip you need to worry about when MTD becomes mandatory.
Download Tripbook from the App Store and start building MTD-compliant mileage records automatically.
