Business Travel Expenses – UK Subsistence, Mileage Allowances, and HMRC Rules

Travel expense accounting and business subsistence represent critical areas where employers can reimburse employees free of Income Tax and National Insurance contributions (NICs) — yet they remain among the most frequent sources of compliance errors during HMRC employer compliance reviews and PAYE audits. In UK tax and employment law, every valid claim hinges upon a fundamental statutory concept.

The Permanent Workplace vs. Temporary Workplace

The determination of a permanent workplace is established through both the employment contract and statutory statutory tests:

1. Contractual definition: The designated office, depot, or operational site specified in the employee's Section 1 written statement of employment particulars (Employment Rights Act 1996).
2. Quantitative tests: If an employee attends a workplace for all or almost all of their working time, or under a continuous pattern of regular attendance, it constitutes a permanent workplace.

Employees with no fixed base — such as mobile service engineers, itinerant construction staff, or visiting care workers — are treated as having no single permanent workplace, meaning their travel between different assignment sites qualifies as business travel.

Subsistence and Meal Allowances (HMRC Benchmark Scale Rates)

When employees undertake business travel to a temporary workplace, employers can reimburse subsistence expenses tax-free. Under the statutory exemption in Section 289A ITEPA 2003, employers may use either actual receipted expenditure or HMRC benchmark scale rates:

There are only these three benchmark rates. The separate breakfast and late evening meal rates that previously sat alongside them were withdrawn with effect from 6 April 2019; where an early start or a late finish needs to be covered above the standard rates, the employer must either reimburse actual receipted costs or agree a bespoke scale rate with HMRC.

To apply HMRC benchmark rates without operating PAYE or reporting on Form P11D:

• The travel must be qualifying business travel to a temporary workplace.
• The employee must have actually incurred expense on food and drink (reimbursing flat allowances when no expenditure occurred is treated as taxable earnings).
• The employer must operate an internal checking and verification system to confirm that journeys actually took place.

Employers may also agree bespoke scale rates with HMRC under an approval notice, supported by sampling exercises demonstrating typical employee spend.

Deductions for Provided Meals

Where the employer, a client, or an event organiser provides a meal free of charge to the employee, subsistence scale rates must be adjusted:

Under HMRC rules, scale rate payments are intended only to cover costs genuinely incurred by the employee. If a meal is provided without cost to the worker, no tax-free scale rate can be paid for that specific meal, regardless of whether the employee chooses not to eat the provided meal.

The 24-Month Rule for Temporary Workplaces

Under Section 339(5)–(6) ITEPA 2003, a workplace ceases to be treated as a temporary workplace if:

1. The employee has been assigned to work there for a period of continuous work lasting more than 24 months, OR
2. It is reasonable to assume (expected) that the assignment will exceed 24 months.

"Continuous work" is defined as any period where duties at that workplace account for 40% or more of the employee's working time.

[!IMPORTANT] The rule applies as soon as the expectation changes. If a 12-month assignment is extended to 30 months in month 10, the workplace becomes a permanent workplace immediately in month 10 — not at month 24. From that date onward, travel and subsistence reimbursements become subject to Income Tax and Class 1 National Insurance.

A significant break in attendance (typically requiring a break of more than one year or a substantial change in duties/location) is required to reset the 24-month clock.

Travel and Mileage Costs (HMRC Approved Mileage Allowance Payments)

When employees use vehicles for qualifying business journeys, statutory rules dictate reimbursement:

Company Cars: Reimbursed using HMRC Advisory Fuel Rates (AFR) or actual electricity rates for fully electric company cars (AER), covering only the business fuel/charging element without taxable benefit.

Personal Vehicles (Approved Mileage Allowance Payments - AMAPs): Under Section 229 ITEPA 2003, employers can pay statutory Mileage Allowance Payments (MAPs) tax-free up to approved limits:

Payments made above these statutory AMAP rates represent taxable earnings subject to PAYE tax and Class 1 NICs. If an employer pays less than the statutory rate (e.g., 30p per mile), the employee can claim Mileage Allowance Relief (MAR) directly from HMRC on their annual tax return or via Form P87.

Public Transport, Taxis, and Parking: Reimbursed tax-free at actual cost against itemised receipts, provided the journey constitutes qualifying business travel.

Accommodation Costs and Incidental Overnight Expenses

Actual overnight accommodation costs incurred for business travel can be reimbursed tax-free against valid VAT receipts and invoices.

Under Section 240 ITEPA 2003, employers may additionally pay Personal Incidental Expenses (PIEs) tax-free to cover personal telephone calls, newspapers, or laundry during overnight business stays:

• UK travel: Up to £5 per night.
• Overseas travel: Up to £10 per night.

If the total incidental expenses exceed the statutory limits for the trip (e.g. £6 per night in the UK), the entire payment becomes taxable, not just the excess.

International Business Travel

For employees travelling abroad on business, HMRC publishes official Worldwide Subsistence Rates (overseas scale rates) covering meal allowances and accommodation for major cities across the globe.

Employers can pay up to the published overseas rates without deducting PAYE tax or National Insurance, provided the employee incurs actual accommodation and subsistence expenditure during a genuine business trip.

Travel Time as Working Time under UK Law

Travel expense reimbursement and statutory working time are governed by separate legal frameworks:

In modern HR and time tracking systems, business travel hours must be tracked under a dedicated time category separate from expense reimbursements. This maintains an audit trail under Regulation 9 of the WTR 1998 and ensures National Minimum Wage compliance.

Key Requirements for an Automated Travel Expense Workflow

To maintain compliance with HMRC, the Employment Rights Act 1996, and UK GDPR:

1. Workplace designation: Clearly record permanent workplaces and contractual bases across all employee digital profiles.
2. Automated absence calculation: Sync departure and return timestamps directly from the time tracking module to prevent discrepancies in subsistence eligibility.
3. Dynamic meal deduction logic: Automatically discount benchmark subsistence rates whenever meals or hotel breakfasts are logged on project bookings.
4. 24-month rule monitoring: Track cumulative duration and working time percentages (40%+ threshold) for all temporary project sites.
5. Mileage tracking & AMAP thresholds: Automatically step down mileage reimbursement from 45p to 25p once the 10,000-mile annual threshold is reached within the PAYE tax year.
6. HMRC & audit-proof digital records: Retain digital receipt archives, VAT invoices, and mileage logs for at least 6 years in compliance with the Taxes Management Act 1970 and National Minimum Wage Regulations.
7. Payroll integration: Segregate non-taxable qualifying expenses from taxable allowances to ensure accurate Real Time Information (RTI) submissions to HMRC.

Sources and Statutory Framework

Legislation and Regulations

• Income Tax (Earnings and Pensions) Act 2003 (ITEPA 2003) — Sections 229–236 (AMAPs), Section 240 (Incidental Overnight Expenses), Section 289A (Exemption for paid or reimbursed expenses), and Sections 336–339 (Travel and Workplace definitions)
• Working Time Regulations 1998 (SI 1998/1833) — Working time definitions, 48-hour weekly limits (Reg 4/5), daily rest (Reg 10), and employer record keeping (Reg 9)
• National Minimum Wage Regulations 2015 (SI 2015/621) — Rules regarding travel time and allowable deductions
• Employment Rights Act 1996 (ERA 1996) — Section 1 particulars regarding location of work

Official Guidance and Case Law

• HMRC Employment Income Manual (EIM31800 - EIM32000) — Travel expenses, permanent and temporary workplaces, and scale rate rules
• HMRC Advisory Fuel Rates & AMAP Guidance — Current mileage and company car advisory rates
• Federación de Servicios Privados del sindicato Comisiones Obreras (CCOO) v Tyco Integrated Security SL (Case C-266/14) — Travel time for peripatetic workers as working time

Status of analysis: August 2026. This article provides operational and legal guidance for UK employers and HR professionals and does not constitute formal legal or tax advisory services in individual cases.