Running a limited company entails numerous expenses, ranging from the obvious, such as office rent and staff salaries, to the less apparent ones that many business owners overlook.
Understanding what you can claim as legitimate business expenses can make a real difference to your tax bill – potentially saving you hundreds or thousands of pounds each year.
The rules for limited companies are different from those for sole traders. As a company director, you face stricter requirements around mixed-use items and personal benefits. Any personal benefit from company-paid expenses creates a benefit-in-kind charge, meaning both you and your company face additional taxes.
This makes the expense rules for limited companies more complex, but also creates opportunities if you understand them properly.
Get it wrong, and you could face penalties from HMRC. Get it right, and you’ll keep more money in your company’s bank account where it belongs.
The Golden Rule: Wholly and Exclusively for Business
Every expense you claim must meet HMRC’s “wholly and exclusively for business” rule.
This means the cost needs to be entirely for business purposes. It’s not enough for something to be mostly for business – it has to be completely for business with no personal element.
However, there’s an important exception that many business owners miss. Where you can identify a definite part or proportion of an expense that has been laid out wholly and exclusively for business purposes, you can claim that specific portion.
The key word here is “identifiable” – you need to be able to clearly separate and measure the business element from any personal element.
For example, if you use your car and can prove that 70% of your mileage is for business purposes, you can claim 70% of your running costs.
But if you buy a laptop that you use for both work and personal activities with no clear way to separate the usage, you can’t claim any portion because there’s no identifiable business-only element.
Note that this differs from the rules for sole traders, where it’s easier to apportion personal and business use.
This is where the “duality of purpose” rule comes in. If an expense is incurred for more than one reason and one of those reasons is not for business purposes, the entire expense fails the test – unless you can identify a specific business proportion.
Understanding Allowable vs Disallowable Expenses
Not all business costs are treated the same way by HMRC. Allowable expenses are ones you can claim back from your company’s profits before working out your Corporation Tax.
These reduce your taxable profits and therefore your tax bill. Disallowable expenses are costs that you can pay through the company, but they won’t reduce the amount of tax you have to pay.
Common disallowable expenses include:
- Client entertainment costs – taking clients out for dinner or to sporting events
- Personal expenses – anything that benefits you personally rather than the business
- Fines and penalties – parking tickets or regulatory fines imposed on the company
- Political donations – contributions to political parties are specifically disallowed
- Most charitable donations – these require special treatment and can’t be claimed as ordinary trading expenses
The Most Commonly Claimed Business Expenses
Let’s run through the expenses that most limited companies can legitimately claim:
Office and Administration Costs
Your day-to-day running costs are typically the most straightforward to claim. This includes office rent, business rates, utilities, insurance, stationery, postage, and telephone bills. These costs are usually easy to justify as wholly business-related.
Staff Costs
Salaries, National Insurance, workplace pensions, and employee benefits are all deductible. This extends to recruitment costs, including job advertisements, agency fees, staff training sessions, workshops, and genuine business-related employee development.
Professional Fees
Accountancy fees, legal costs, bank charges, and certain professional subscriptions qualify as allowable expenses. However, professional subscriptions must be to organisations on HMRC’s approved List 3, and the membership must be necessary for your business or help maintain your professional competence.
Travel and Transport
Business travel costs are claimable, but personal commuting isn’t. Journeys between home and your regular office are classed as ordinary commuting and are not allowable. However, travel to temporary work locations, client meetings, or business conferences all count as legitimate business expenses.
If you use your personal car for business, your company can reimburse you using HMRC-approved mileage rates. These rates cover fuel, wear and tear, and general running costs – currently 45p per mile for the first 10,000 miles and 25p per mile thereafter.
Working From Home Expenses
Many business owners work from home but miss out on claiming associated costs.
HMRC allows directors of limited companies to claim a flat-rate allowance for using their home as an office. For the 2024/25 and 2025/26 tax years, this is £6 per week, totalling £312 annually.
This flat-rate method is simple and doesn’t require detailed records or calculations. Most importantly, it doesn’t create any capital gains tax complications when you sell your property.
Alternatively, if you use a significant portion of your home exclusively for business, you can calculate actual costs based on the proportion used.
However, this comes with a serious warning: if you claim a proportion of your home as exclusively business use, you may face Capital Gains Tax on that portion when you sell your property. This is why most company directors stick to the weekly allowance.
If you do choose the actual costs method, you’ll need a formal rental agreement between yourself and your company, and you’ll have to declare the rental income on your personal tax return.
Capital Allowances: When Equipment Becomes an Asset
When you buy expensive equipment for your business – computers, machinery, vehicles, or office furniture – these are often treated as capital assets rather than immediate expenses. However, the good news is that you can usually claim the full cost in the year of purchase through the Annual Investment Allowance (AIA).
The AIA currently allows you to claim up to £1 million per year on qualifying plant and machinery. This covers most business equipment including computers, office furniture, machinery, and commercial vehicles.
For cars, the rules are more complex and depend on CO2 emissions. Electric vehicles and low-emission cars qualify for enhanced allowances, while high-emission vehicles are subject to lower rates of relief.
Phone Bills and Communications
Communication costs can be complex for limited companies. If the mobile phone contract is in the company’s name and used for business purposes, the full cost is an allowable expense.
HMRC allows companies to provide one mobile phone per employee without creating a benefit-in-kind charge, provided the contract is between the company and the supplier.
If you’re paying for your personal phone but using it for business, you can only claim the business portion of your calls. However, line rental costs are generally not deductible unless the phone is used exclusively for business, which can be difficult to prove with modern phone packages.
Benefits in Kind: When Expenses Become Taxable
Here’s where many business owners get caught out. If your company pays for something that benefits you personally, it becomes a benefit in kind (BIK), which means both you and your company face additional tax charges.
Common examples include:
- Personal use of company cars
- Private medical insurance
- Gym memberships
- Personal elements of phone bills
- Accommodation that’s not solely for business
As a director, when a BIK arises, you personally pay income tax on the benefit value through your tax code or self-assessment, while your company pays Class 1A National Insurance. This double taxation can make seemingly attractive company perks expensive once you calculate the real cost.
There are some exemptions that directors should know about, including trivial benefits under £50 per occasion (with an annual limit of £300 for directors), and certain items like one company mobile phone per director.
These exemptions can be useful for small rewards or recognition without triggering tax charges.
Record-Keeping: Your First Line of Defence
Pay from your business bank account whenever possible. If you end up paying business bills yourself, process the reimbursement through the company later, but maintain a clear paper trail.
HMRC can ask to see evidence for any expense claim, so maintaining detailed records is essential. You must retain records as evidence for six years after the end of the accounting period. This includes:
- Original receipts or invoices
- Bank statements showing payments
- Business justification for each expense
- Mileage logs for vehicle expenses
- Evidence of business purpose for mixed-use items
Digital storage is widely accepted, so you don’t need to keep physical copies if you have secure digital versions.
Read our article on accounting tips for founders here.
Common Mistakes That Cost Money
Many business owners make expensive errors when claiming expenses. Here are the most frequent issues:
- Overclaiming on mixed-use items – claiming 100% of costs when there’s clear personal use will almost certainly trigger HMRC attention.
- Missing the business purpose test – expenses need a clear business rationale, not just a loose connection to your work.
- Poor record-keeping – without proper documentation, even legitimate expenses can be rejected.
- Treating capital items as expenses – expensive equipment should usually go through capital allowances, not be claimed as immediate expenses.
- Ignoring benefit in kind rules – if something benefits you personally, it likely creates a tax liability that needs to be reported.
Making the Most of Your Allowable Expenses
The expense rules exist to ensure businesses only pay tax on their actual profits, not their turnover. By understanding what you can legitimately claim, you’re simply ensuring you’re not paying more tax than legally required.
Consider setting up proper systems for tracking expenses throughout the year rather than scrambling at year-end. Modern accounting software can categorise expenses automatically and flag potential issues before they become problems.
Remember that tax rules change regularly. What’s allowable today might not be tomorrow, so staying informed or seeking professional advice is crucial.
Understanding your limited company’s allowable expenses can save you significant money each year while keeping you compliant with HMRC.
At Double Point, our chartered accountants help businesses maximise legitimate expense claims while staying within the rules. Book a free consultation today to ensure you’re claiming everything you’re entitled to.