Sole traders can obtain tax relief on various expense costs. This overview looks at allowable and disallowable expenditure, focussing on some of the things that need to be considered when deciding if expenditure is allowable or disallowable for tax purposes.
What are allowable expenses?
Allowable expenses are the expenses that have been included in the profit and loss account and are also allowable for tax purposes. This means that the sole trader will get a tax deduction for these expenses.
Contact the the GOV.UK Self Assessment helpline if you’re not sure whether a business cost is an allowable expense.
The two rules you need to know
There are specific rules relating to some items such as entertaining, fines and legal expenses but the two general rules to be aware of are as follows:

‘Wholly and exclusive’
1. Expense must be ‘wholly and exclusive’ for business use. This means that the expense must have been incurred by a business purpose for a business purpose and there is no private benefit.
Where an expense is incurred and there is a mix of business and personal use, if you are able to apportion on a reasonable basis then the business portion is allowable, e.g motor expenses, as these can be apportioned on a mileage basis.
Where there is mixed use (both business and private) and it is not possible to apportion on a reasonable basis, then the whole cost is disallowed e.g a gym membership which includes the gym facilities and occasional networking events.

Revenue expenditure
2. Expenditure must be revenue, not capital in nature. Capital expenditure is deemed to be items purchased in the business which provide an ‘enduring benefit’ to the business.
In other words, you expect to use for the long term; two years or more. Revenue expenditure is the day-to-day expenditure.
Examples of allowable expenses include:
- office costs
- travel costs
- clothing expenses
- staff costs
- things you buy to sell on
- financial costs
- costs of your business premises
- advertising or marketing.
Which expenses are disallowable?
Most of the expenses that a business incurs meet the ‘wholly and exclusive’ test and are therefore allowable. Items such as staff wages, materials, business travel, postage etc do not cause a problem. Let’s now look at the areas that may contain disallowable expenditure and the reasons why.
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Repairs and renewals
Repairs and renewals will be only allowable if they are revenue in nature. This means that they are day-to-day expenses and they are not enhancing or improving an asset – i.e. not making the asset more valuable. If they enhance or improve, then the cost is treated as capital. The full cost will not be deductible immediately (usually) but capital allowances may be available. Speak to a professional about the availability of the annual investment allowance (AIA).
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Legal costs
Expenditure will only be allowable if it is related to the day-to-day business activity e.g the legal costs in chasing bad debts. Expenditure relating to personal activity such as legal costs to defend personal reputation and legal costs associated with fines and penalties are disallowed. Legal costs in relation to the purchase of capital items are disallowed, but once again capital allowances may be available.
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Entertaining
The cost of entertaining clients is disallowed but the cost of entertaining employees is allowable (although be careful you don’t entertain them too much as they may attract a benefit, which will be taxable on the employee and attract national insurance).
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Donations
Charitable donations are generally disallowable as are political donations. Local donations made for the the purpose of the trade i.e. no private benefit to the owner may be allowable. In practice, you will need to prove here that there is a business purpose for making the donation.
What are simplified expenses?
Simplified expenses are a way of calculating some of your business expenses using flat rates instead of working out your actual business costs. The aim is to ease the administration burden on small business.
You don’t have to use simplified expenses. You can decide if it suits your business.
You can use simplified expenses if:
- You use your car for business (you would need to keep a record of the number of business miles)
- You use part of your home for business use (e.g. a workshop or an office)
- You use your business premises for home (e.g. you live above a pub).
Can I use simplified expenses?
You can use simplified expenses if you are a sole trader or a partner in a partnership (as long as all of the partners are individuals). Simplified expenses can’t be used by limited companies or business partnerships involving a limited company.
If you use simplified expenses, you will note this on your tax return.
How do I claim allowable expenses?
You will claim all of your allowable expenses on your self assessment tax return.
You are able to break down the types of expenses as part of your return or you may be able to use the ‘three line account’ method which is simpler if your turnover is below the VAT registration threshold (currently at £85,000).
The ‘three line account’ method is a simple way of giving details of your income and expenses to HM Revenue & Customs (HMRC).
Checklist: What records do I need to keep?
It is vital that books and records are kept safely as there are rules surrounding how long business records must be stored for. Information that you will need to keep to prepare your accounts can be found below. Login to save this checklist to your profile for future use – as you work through the list, any checkboxes that are ticked or unticked will be automatically saved to your profile. (To register to join and enjoy the benefits of membership click on the link at the top right of the page. It will only take a few minutes to create your profile).
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