What Counts as a Business Expense? A Complete Guide
Understanding what qualifies as a business expense (or allowable expense) is an important part of running a business. As well as keeping your records in order, correctly recording business expenses ensures that you don't pay more tax than necessary while staying compliant with HMRC rules.
The rules themselves are relatively straightforward, but in practice, this is an area where many business owners either underclaim or unintentionally get things wrong.
This guide explains what counts, what doesn't and how to approach your business expenses with confidence.
What is a Business Expense?
A business expense is a cost you incur while running your business. In most cases, these costs can be deducted from your income when working out your taxable profit, reducing the amount of tax you pay.
The key principle from HMRC to keep in mind is:
An expense must be “wholly and exclusively” for business purposes.
This doesn't mean there can never be any personal benefit. What matters is that the main purpose of the expense should be business-related. Where there is a mix of personal and business use, you can usually claim the business portion, as long as you can justify it.
Why getting it right matters
Claiming the correct business expense amounts ensures you are not overpaying tax and also helps keep you on the right side of HMRC.
Your tax is based on profit, not turnover. Therefore, every allowable expense reduces the profit you are taxed on, helping improve your overall cash flow. At the same time, incorrect claims can lead to enquiries or penalties, so accuracy is just as important as maximising what you claim.
Common types of business expenses
Although every business is different, most expenses fall into a handful of core categories.
Day-to-day running costs
These are the regular costs of keeping your business operating. They include items such as stock or raw materials, stationery, software subscriptions and general office expenses.
If you work from home, you may also be able to claim part of your household costs.
- If you're a sole trader, HMRC offers a simplified flat rate based on the number of hours you work from home each month.
- If you run a limited company, the rules are slightly different. You can charge your company a small flat allowance for home office use or claim a proportion of your actual household costs based on business use.
Either way, it's worth getting advice to make sure you're using the most appropriate method.
Travel costs
Travel is allowable where it is genuinely for business purposes. This includes things like train fares, mileage, parking and overnight accommodation when working away.
It's worth noting that travel between your home and a regular workplace is treated as commuting and is not an allowable business expense.
Staffing costs
If you employ staff or use subcontractors, their costs can normally be claimed. This includes wages, pensions and employer National Insurance contributions.
Premises and overheads
For businesses with premises, costs such as rent, utilities, maintenance and repairs are typically allowable. Even if you don't have separate premises, you may still be able to claim a proportion of these costs incurred when working from home.
Marketing and professional costs
Expenses that support or grow your business are also usually allowable. This might include website costs, advertising, insurance and professional fees such as accountancy or legal advice.
What you can't claim
Understanding what doesn't qualify as a business expense is just as critical. Whether a cost is claimable depends on HMRC's rules, not simply whether it feels business-related.
Common non-allowable expenses include:
- Personal purchases
- Everyday clothing (even if worn for work)
- Client entertainment
- Fines and penalties
These are either seen as personal or specifically disallowed, regardless of how closely they relate to your business activity.
Mixed-Use Expenses: What You Need to Know
Mixed-use expenses are one of the most common areas where mistakes happen. In reality, many costs are not purely business or purely personal. Things like mobile phones and broadband costs often fall somewhere in between. In these cases, only the business element can be claimed, and you should use a reasonable and consistent method to calculate the split.
It's also worth noting that some expenses are treated differently depending on your business structure. For example, a mobile phone provided through a limited company can often be claimed in full, even with some personal use, as long as the contract is in the company's name. Whereas HMRC guidelines for broadband are more restrictive. If you already have a personal home internet contract, reclaiming the cost through a limited company can create tax implications, and in many cases, the full amount will not be allowable.
Because of these differences, it's important to understand how each expense is set up, not just how it is used.
Keeping your records in order
Accurate records underpin every successful business expense claim. As a general rule, you should:
- Keep receipts and invoices
- Record what each expense relates to
- Use software or systems to stay organised
- Retain records for at least six years
This makes tax returns easier and gives you confidence if HMRC ever asks questions.
Understanding what counts as a business expense is an essential part of managing your finances effectively and ensuring you only pay the tax you need to. If you're ever unsure, seeking advice early can save time, reduce stress and ensure you're claiming everything you're entitled to without taking unnecessary risks.
If you'd like support with reviewing your expenses or putting better systems in place, our accountancy services can make the process much simpler and give you peace of mind going forward.
Please get in touch with our team to find out more.