Ask any small business owner what causes the most low-level friction in their team, and expenses usually feature near the top. Someone books a first-class train ticket to Edinburgh without thinking twice. A sales rep claims a Friday-night dinner as a "client meal" — the client wasn't there. A manager approves a £400 software subscription that duplicates a tool you already pay for. None of these things happen because people are dishonest; they happen because no one ever wrote down what was and wasn't acceptable. A solid business expense policy fixes that. Done well, it also makes your year-end accounts cleaner, your HMRC submissions more defensible, and your cash flow easier to forecast.
Why Your Business Needs a Written Expense Policy
Plenty of UK small businesses operate on a nod-and-a-wink basis when it comes to expenses — especially those with fewer than ten staff. The owner approves everything informally, receipts pile up in a shoebox, and come January the accountant spends hours trying to reconstruct what was a legitimate business cost and what wasn't. That approach works until it doesn't.
HMRC is clear that expenses must be incurred "wholly and exclusively" for the purposes of the business to be deductible. That phrase carries real weight. If you're ever subject to a compliance check, you'll need to demonstrate not just that you have receipts, but that the expenditure was genuinely business-related. A written policy gives you that audit trail. It shows a systematic approach to expense management rather than ad hoc decision-making.
There's also the matter of staff fairness. Without written rules, perceived inconsistency breeds resentment. If one employee gets a £50 team lunch approved without question while another has a £30 taxi claim queried, you have a people problem as much as a financial one. A policy removes the subjectivity.
Define Your Expense Categories and Spending Limits
The backbone of any expense policy is a clear list of categories with associated spending limits. Think about the types of costs your employees genuinely incur, then set thresholds that are realistic but not open-ended. Common categories for UK SMEs include:
- Travel: Rail, flights, taxis, and parking. Consider capping standard rail travel at second class unless a journey exceeds, say, three hours.
- Accommodation: Set a nightly rate limit — for London, something in the region of £150–£180 is reasonable for a mid-range hotel; outside the capital, £100–£120 is often sufficient.
- Subsistence: Daily meal allowances when away from the usual place of work. HMRC's benchmark scale rates are a sensible starting point: £5 for breakfast, £10 for a one-meal stop, and up to £25 for longer trips.
- Client entertainment: Worth treating with extra care, as HMRC does not allow you to deduct the cost of entertaining UK clients against corporation tax, even if it's a legitimate business activity. Make this explicit in your policy so there are no nasty surprises.
- Mileage: HMRC's approved mileage allowance payment (AMAP) rates currently sit at 45p per mile for the first 10,000 miles in a personal vehicle and 25p thereafter. Reimburse at these rates and you avoid a benefit-in-kind charge.
- Equipment and software: Specify an approval threshold — anything above, say, £100 might require a line manager sign-off; above £500 might need director approval.
Writing these limits down takes less than an afternoon. The clarity it creates lasts for years.
Set Out Your Receipt and Submission Requirements
No receipt, no reimbursement. It sounds blunt, but it's the right stance. HMRC expects documentary evidence for any expense you're claiming as a deduction, and that evidence needs to show the date, the supplier, a description of what was purchased, and the amount including VAT where applicable.
Decide on a minimum threshold below which you'll accept a written note in lieu of a receipt — many businesses set this at £10 or £25 for very small incidental costs. Above that threshold, a physical or digital receipt is non-negotiable.
Equally important is your submission deadline. Requiring employees to submit expenses within 30 days of incurring them is standard practice. It keeps your bookkeeping current, prevents year-end backlogs, and means you're not approving a claim for a meal that happened six months ago when context is long forgotten.
Tools like BizHub365 include AI-powered receipt scanning, which means employees can photograph a receipt on their phone and have it automatically parsed and categorised — supplier name, date, amount, and VAT extracted in seconds. That removes the friction of manual data entry and reduces the risk of receipts going missing before they reach the accounts team.
Build a Simple, Clear Approval Process
An expense policy without an approval process is just a list of suggestions. You need to define who approves what, and how quickly. A tiered approach works well for most SMEs:
- Routine claims under a set threshold (e.g., under £50): self-certified by the employee, spot-checked by the finance function monthly.
- Mid-range claims (e.g., £50–£500): approved by a direct line manager before submission to payroll or accounts.
- Large or unusual claims (e.g., over £500, or anything in an unusual category): requires director or finance director sign-off.
Commit to a turnaround time for approvals — five to seven working days is reasonable. Employees who are out of pocket deserve a prompt response. Slow reimbursement is a surprisingly common cause of staff dissatisfaction, particularly among junior team members for whom a £200 expense might represent a meaningful chunk of their monthly budget.
Where possible, automate this workflow. Platforms that link expense submission to an approval queue reduce the chance of claims being lost in someone's inbox and give you a clear digital audit trail for every decision made.
Communicate the Policy — and Keep It Current
A policy that lives in a shared drive folder, never mentioned again after it was written, is barely better than no policy at all. Introduce the expense policy during employee onboarding. Include it in your staff handbook. When you update it — and you should review it at least annually — send a brief note to all relevant staff explaining what's changed and why.
Changes to HMRC's approved mileage rates, shifts in benefit-in-kind thresholds, or updates to the scale rates for subsistence can all affect what you should be reimbursing. The Spring Budget and Autumn Statement are good prompts to revisit your policy each year.
Be transparent about the reasons behind your rules. If you've capped hotel spend at £130 per night, explain that this is based on typical rates outside London and that exceptions can be requested in advance for trips to central London or Edinburgh during peak periods. People accept rules far more readily when they understand the reasoning.
Conclusion
A well-crafted expense policy is one of those small administrative investments that pays back disproportionately. It reduces disputes, speeds up your month-end close, keeps HMRC claims watertight, and signals to your team that the business is run professionally. Start simple: draft your categories and limits, set your receipt requirements, define your approval chain, and write it all down in plain English. Then make sure everyone actually reads it.
If you're looking to take the administration out of the day-to-day, BizHub365 brings expense tracking, receipt scanning, and bookkeeping together in one place — built specifically for UK small businesses and fully aligned with HMRC's Making Tax Digital requirements. The policy is your framework; the right tools make it effortless to enforce.