Mileage and home-as-base
If a hybrid employee's contractual base is home, the first commute of the day to a customer is reimbursable. If their base is the office, it isn't. Get the policy clear and the HMRC position documented; it removes the most common dispute. The 'temporary workplace' rules under HMRC EIM32000 still apply, and the 24-month test still kicks in for travel to a single secondary site. Spell out the home-as-base employees in the policy and link to the relevant HMRC guidance — auditors and employees both appreciate the explicit reference.
Home office equipment
A one-off setup allowance (e.g. £250) plus an annual top-up (e.g. £100) covers most cases without endless one-off claims. Specify what's in scope (desk, chair, monitor, peripherals, ergonomic accessories) and what's not (decor, art, smart-home devices). The £6/week home working allowance under ITEPA s316A is a separate question — decide whether you fund it and document the decision. Employers who provide the equipment outright usually get better tax treatment than employers who reimburse employee purchases; ask your accountant before finalising.
Software subscriptions and AI tools
Employees buying their own AI tools, dictation apps and productivity subscriptions is the new shadow IT. Either provide an approved list with a monthly stipend, or accept individual reimbursements with a security review — but don't pretend it's not happening. The security review is the important part: a personal-account ChatGPT Plus subscription used for company data is a data-protection issue, regardless of whether it is reimbursed. Build a short approved-list of AI tools with a single-sign-on and corporate billing, and the shadow-IT problem mostly disappears.
Working-from-anywhere policies
Employees increasingly want to work from abroad for short periods — a few weeks in summer, family visits, partners on overseas assignments. This creates payroll, tax-residency and data-residency questions that the expense policy alone cannot answer, but the policy should set the rules: maximum days per year, advance notification required, prohibited countries (sanctions and data-residency reasons), and the employee's responsibility for any personal-tax consequences. Without the rules, you get ad-hoc decisions that create precedents.
Per diems and city tiers
Per diems were simple when everyone travelled to the same handful of cities. With hybrid teams and distributed travel, per diem tables need annual updating and city-tier grouping (Tier 1: London, NYC, Tokyo; Tier 2: Manchester, Berlin, Singapore; Tier 3: everywhere else). Publish the table inside the expense system so requesters see the limit before they spend, not after.
Receipts, evidence and audit
HMRC accepts digital receipts, but they must be legible and contain the same information as the paper original. Build a receipt-capture flow into the expense system that takes the photo at the point of spend; relying on employees to photograph receipts at month-end produces blurry, missing or duplicated images. The flow is the policy enforcement; the written policy is just the documentation.
Treat the policy as a product
Expense policies are most often updated after a dispute. Treat the policy as a product instead: scheduled annual review, version-controlled, change log published to the team, and a single owner. The shift from 'document' to 'product' produces a shorter, clearer, more current policy and fewer disputes — because everyone knows the rules and the rules match the operation.
A modern expense policy is shorter, clearer and updated annually. Treat it as a product, not a legal document — and the disputes mostly disappear.