Managing HMRC travel and subsistence expense compliance is one of the most consequential—and commonly mishandled—obligations facing UK finance and HR teams. Errors in expense classification, insufficient audit trails, or misapplication of rules such as the 24-month temporary workplace rule can trigger PAYE investigations, backdated tax liabilities, and financial penalties that far outweigh the original claims. For organisations processing expenses at scale, the risk compounds quickly: a single policy gap applied consistently across a workforce becomes a systemic compliance failure.
This article breaks down the key HMRC rules governing travel and subsistence expenses—including qualifying journey criteria, meal allowance thresholds, mileage rates, and evidential requirements—so you can identify where your current processes are exposed and leave with a clear framework for bringing them into compliance.
HMRC Mileage Allowance Rates and the 24-Month Temporary Workplace Rule #
HMRC sets Approved Mileage Allowance Payment (AMAP) rates that determine how much employers can reimburse employees tax-free for using personal vehicles on business trips. For cars and vans, the rate is 45p per mile for the first 10,000 miles in a tax year, dropping to 25p per mile beyond that threshold. Motorcycles are reimbursed at 24p per mile, and bicycles at 20p per mile, regardless of distance. If you pay above these rates, the excess is treated as taxable income. If you pay below them, employees can claim Mileage Allowance Relief directly from HMRC for the shortfall.
The 24-month temporary workplace rule determines whether a work location qualifies for mileage relief in the first place. HMRC defines a temporary workplace as one where an employee attends for a limited duration or purpose. Critically, if an employee is expected to work at a single location for more than 24 months—or if that location becomes their only workplace—it loses temporary status and becomes a permanent workplace. Commuting costs to a permanent workplace are never tax-deductible.
The rule resets only if attendance at that site drops below 40% of working time, or if the employee moves to a genuinely different posting. A common failure mode is assuming that a rolling contract extension keeps the workplace temporary — it does not. Once it becomes clear the placement will exceed 24 months, the tax treatment changes from that point forward, not just at the 24-month mark. Employers who continue reimbursing mileage without reassessing workplace status risk creating unreported taxable benefits.
Subsistence Allowance Eligibility and Qualifying Journey Conditions #
HMRC permits subsistence claims only when an employee travels to a temporary workplace — not their regular place of work. The journey must be made wholly and exclusively for business purposes, and the employee must be away from their normal base for a period that makes it unreasonable to return for meals or overnight rest. Commuting costs and meals purchased on a standard commute are explicitly excluded.
The 24-month rule is a critical threshold here too. If an employee attends the same temporary site for more than 24 months — or is expected to spend more than 40% of their working time there — HMRC reclassifies it as a permanent workplace. From that point, subsistence claims for that location are no longer permitted. Finance teams frequently overlook this when approving long-running project placements.
For 2026, HMRC benchmark rates are: £5 for absences of five hours or more, £10 for ten hours or more, and £25 for absences of fifteen hours or more (or if the employee is away from home overnight). An additional £10 late evening meal rate applies where the employee works later than usual and incurs a meal cost as a direct result.
A common failure mode is claiming subsistence on a day where the journey was not genuinely temporary or business-driven. A consultant who travels to the same client office daily for 26 months cannot claim meal allowances for that site, even if the assignment was originally framed as short-term. Claims require evidence that the journey qualified, the meal was necessary, and receipts or benchmark rates were applied correctly.
Evidence and Documentation Requirements for Compliant Expense Claims #
HMRC requires employers to retain clear, original evidence for every travel and subsistence claim. For mileage, this means a log that records the date of each journey, the start and end points, the business purpose, and the total miles driven. For subsistence, you need itemised receipts showing the date, vendor, and amount — a card statement alone is not sufficient, because it does not confirm what was purchased.
Finance teams must verify four things before approving any claim: whether the journey qualified under HMRC rules (including the 24-month temporary workplace threshold), whether the meal was eligible given the duration and nature of the trip, whether the correct evidence was provided, and whether the claim adhered to internal policy. Missing any one of these checks creates exposure.
A common failure mode is approving claims on the basis of a summary spreadsheet without underlying receipts. During an HMRC audit, the burden falls on the employer to demonstrate compliance. If supporting documentation cannot be produced, the reimbursement may be reclassified as taxable earnings, triggering additional income tax and National Insurance liability — potentially backdated across multiple tax years.
Records must be retained for a minimum of six years from the end of the relevant tax year. Digital copies are acceptable provided they are legible and accurately reproduce the original. Organisations that rely on paper-based or email-driven processes frequently discover gaps at this point, which is why a consistent capture and storage process matters well before an audit arises.
Setting Company Expense Policies and Approval Workflows #
A well-structured expense policy removes ambiguity for employees and gives finance teams a consistent basis for review. Start by setting spending limits for each category — meals, accommodation, ground transport — rather than applying a single blanket cap. For example, a daily meal allowance aligned with HMRC’s benchmark subsistence rates (£5 for qualifying five-hour journeys, £10 for ten hours) gives employees a clear ceiling while keeping the company within tax-compliant territory.
Approval authority thresholds matter as much as the limits themselves. Define exactly who can sign off standard claims and who must authorise anything above a set value — say, expenses exceeding £250 or overnight stays outside a designated city list. Without this structure, high-value claims routinely bypass scrutiny simply because no one is certain whose job it is to question them.
Non-standard claims need their own workflow. A common failure mode is treating unusual requests — last-minute flights, client entertainment, extended stays — through the same process as routine receipts. Build a separate approval path that requires a brief written justification and a second authoriser.
Policy alignment with HMRC rules is not optional. Claims must satisfy the qualifying journey test, include appropriate evidence, and follow company policy — all three conditions, not just one. Finance teams should audit a sample of subsistence claims quarterly to catch systematic errors before they accumulate into a compliance problem. Documenting the policy in writing and communicating it during onboarding reduces both fraud and unintentional misuse.
Tax Relief Implications for Employers and Employees on Travel Reimbursements #
When an employer reimburses genuine business travel costs — such as rail fares to a temporary workplace or mileage driven to a client site — those payments are free from both income tax and National Insurance Contributions (NICs), provided they meet HMRC’s qualifying criteria. The reimbursement must cover actual expenditure, the journey must have a business purpose, and the workplace must not be a permanent base for that employee. Get this wrong and the reimbursement becomes a taxable benefit, triggering a PAYE liability for the employer and an income tax bill for the employee.
The most common failure mode is treating a regular commute as business travel. HMRC’s 24-month rule is specific: if an employee spends more than 40% of their working time at a single location for a period expected to exceed 24 months, it becomes a permanent workplace and travel costs to it are no longer tax-free.
For mileage, HMRC’s AMAP rates set the tax-free ceiling — 45p per mile for the first 10,000 miles and 25p thereafter for cars. Paying above these rates creates a taxable excess; paying below them allows employees to claim Mileage Allowance Relief directly from HMRC.
Employers handling a high volume of irregular expenses can apply for a PAYE Settlement Agreement (PSA), allowing them to settle any resulting tax liability in a single annual calculation rather than processing it through payroll. Where expenses are consistently compliant, a formal dispensation arrangement can remove the need for P11D reporting entirely.
Practically, businesses should document the business purpose of every journey, apply spending controls by expense category, and review whether frequent destinations have crossed the 24-month threshold — before HMRC does.
Building a Compliance-Ready Expense Process #
Staying ahead of HMRC travel and subsistence compliance is not a box-ticking exercise — it is a business-critical discipline that protects your organisation from penalties, audit risk, and reputational damage. Businesses that invest in clear expense policies and consistent documentation practices are far better positioned to withstand scrutiny and maintain employee trust. Robust expense management software makes compliance scalable, reducing manual effort while enforcing policy rules automatically across your workforce.
To act on what you have read, work through this prioritised checklist:
✅ 1. Review your current travel and subsistence expense policy against the latest HMRC guidelines.
✅ 2. Audit your receipt and documentation processes to ensure every claim is fully evidenced.
✅ 3. Define and communicate clear eligibility rules for subsistence, mileage, and accommodation claims.
✅ 4. Implement or evaluate expense management software that enforces policy compliance at the point of submission.
✅ 5. Schedule a regular compliance review — at minimum annually — to capture HMRC rule changes before they create exposure.