15 July 2026 – written by Steffen Kemmerzehl – Friendly Assist Accountancy – Blog
Running a business is busy enough
When you first start working for yourself, keeping things simple often feels like the easiest option.
You buy materials with the same bank card you use for your weekly shopping. You pay for fuel on the way to a customer, stop for a coffee and then pay your mobile phone bill. Everything comes out of the same account.
At the time, it rarely feels like a problem.
Many sole traders, contractors and small business owners do exactly the same thing. Months later, however, when it is time to prepare your accounts or complete your Self Assessment tax return, those small decisions can create hours of extra work. Every transaction needs to be reviewed to determine whether it relates to your business or your personal finances.
At Friendly Assist Accountancy, this is one of the most common bookkeeping issues we help clients resolve. Fortunately, it is also one of the easiest to avoid.
Can I use a personal bank account for my business?
This is one of the questions we are asked most often.
For many sole traders, the answer is yes. There is generally no legal requirement to have a separate business bank account.
However, there is an important difference between something being legally permitted and it being good business practice.
Keeping your business finances separate makes it much easier to:
- Keep accurate bookkeeping records.
- Monitor your business performance.
- Prepare your Self Assessment tax return.
- Understand your cash flow.
- Meet your Making Tax Digital obligations.
- Respond quickly if HMRC requests further information.
A dedicated business account provides a much clearer picture of how your business is performing and significantly reduces the time spent reviewing transactions later.
Why accountants ask questions about your transactions
Clients are sometimes surprised by the number of questions their accountant asks when preparing accounts.
The reason is simple. We have a professional responsibility to ensure your records are accurate before submitting information to HMRC.
A bank statement may show only “Card Payment” or “Transfer”. That tells us very little. Was it business equipment, household shopping, fuel, a loan or simply money moved between your own accounts?
Rather than making assumptions, we ask questions to ensure your accounts are accurate and your tax position is correct. Keeping organised records throughout the year means fewer queries and a smoother year end.
The bookkeeping issues we see most often
No two businesses are the same, but many bookkeeping problems follow similar patterns.
Business purchases are often spread across several bank accounts. Personal transfers appear alongside customer payments. Fuel purchases include both business and private travel. Receipts are misplaced, subscriptions continue long after they are needed or business expenses are paid using whichever card happens to be available.
None of these situations are unusual.
The difficulty is that every unclear transaction takes additional time to review. Over a full year, a handful of small decisions can create many hours of extra bookkeeping work.
HMRC’s golden rule: “Wholly and Exclusively”
When claiming business expenses, HMRC’s starting point is straightforward.
An expense must be incurred wholly and exclusively for the purposes of your trade.
Where an expense has both a business and personal purpose, you can generally only claim the business proportion. This commonly applies to mobile phones, home broadband, vehicles and home office costs.
Keeping accurate records throughout the year makes these calculations much simpler and provides evidence should HMRC ever request further information.
What business expenses can usually be claimed?
Every business is different, but genuine business expenses often include:
- Tools and specialist equipment.
- Protective clothing.
- Business mileage and travel.
- Advertising and marketing.
- Website costs.
- Business insurance.
- Accounting fees.
- Professional memberships.
- Office stationery.
- Business software.
The important question is always the same.
Was the expense incurred wholly and exclusively for the purposes of your business?
If the answer is yes, and HMRC’s conditions are met, it is generally allowable for tax purposes. If you are ever unsure whether an expense is allowable, our UK Tax Help for Individuals, Landlords, Self-Employed People and Small Businesses service explains how we can help.
What expenses are not normally allowable?
Paying for something from your business account does not automatically make it a business expense.
Examples that are generally not allowable include weekly food shopping, family holidays, everyday clothing, personal entertainment, school costs, personal gym memberships and money withdrawn from the business for personal use.
If there is no genuine business purpose, tax relief is unlikely to be available.
Why mixed transactions create problems
Imagine looking through a year’s worth of bank statements.
Alongside payments for tools and materials are supermarket purchases, streaming subscriptions, children’s clothing, household bills and transfers between accounts.
Your accountant now has to establish which transactions relate to the business and which do not. Sometimes receipts are missing. Sometimes additional explanations are needed. Occasionally there is not enough evidence to support a claim.
The result is more questions, more time reviewing records and often higher bookkeeping costs.
Technology helps, but it cannot replace good records
Modern bookkeeping software can automatically import transactions from many UK banks and save considerable time.
However, software cannot always identify whether a payment is business related, personal, a reimbursement, a loan or drawings. Every business still benefits from regular review by someone who understands the transactions.
Bank statements also show where money was spent, but not always what was purchased. Keeping digital copies of receipts provides valuable supporting evidence and makes preparing your accounts much easier.
A few simple habits can save hours later
Good bookkeeping is largely about consistency.
Simple habits that make a real difference include:
- Opening a dedicated business bank account.
- Keeping digital copies of receipts.
- Recording expenses regularly instead of leaving everything until January.
- Paying business expenses from your business account whenever possible.
- Reviewing your bookkeeping every month.
These small changes improve the quality of your records, reduce errors and make preparing your accounts much easier.
Is your bookkeeping working for you?
It may be time to review your bookkeeping if you regularly pay business expenses from your personal account, cannot explain every transaction on your bank statement, leave your records until the tax deadline or feel overwhelmed every time you open your bookkeeping software.
Improving your records today is almost always easier than trying to reconstruct them months later.
Making Tax Digital makes good bookkeeping even more important
Making Tax Digital is changing the way many sole traders and landlords keep records and report information to HMRC.
Businesses with organised bookkeeping are likely to find the transition straightforward. Those with hundreds of mixed personal and business transactions may find quarterly reporting considerably more time consuming.
Good bookkeeping today makes future compliance much easier.
Good bookkeeping supports better business decisions
Bookkeeping is about far more than meeting your tax obligations.
Accurate records help you understand how your business is performing, monitor cash flow, identify spending trends, plan for future tax liabilities and make informed decisions with confidence.
Clear financial records also make it much easier to respond if HMRC ever asks questions.
How Friendly Assist Accountancy can help
At Friendly Assist Accountancy, we work with sole traders, contractors, landlords and small business owners throughout the year to help them keep accurate records, understand their finances and meet their HMRC obligations.
Whether you are just starting your business or have been trading for many years, organised bookkeeping saves time, reduces stress and provides a stronger foundation for making business decisions.
Keeping your business and personal finances separate may seem like a small change, but it can save hours of work, reduce unnecessary costs and give you greater confidence that your records are accurate.
If you have any questions about bookkeeping, allowable business expenses or Making Tax Digital, please get in touch. We are always happy to help.
Frequently Asked Questions
Can I use my personal bank account as a sole trader?
Yes. Most sole traders can use a personal bank account, although having a separate account is generally considered best practice because it keeps bookkeeping simpler and your records more organised.
Can I claim expenses that are partly personal and partly business?
Usually, yes. However, you can generally only claim the business proportion, so accurate records are essential.
What happens if I accidentally claim personal expenses?
HMRC may disallow the expense, meaning additional tax could become payable. Depending on the circumstances, interest or penalties may also apply.
Is a business bank account legally required?
For most sole traders, no. However, separating your business and personal finances is one of the simplest ways to improve bookkeeping and reduce mistakes.
Can an accountant help organise my bookkeeping?
Absolutely. An accountant can help you establish effective bookkeeping processes, identify allowable expenses, improve the quality of your records and help you meet your tax obligations.
Steffen Kemmerzehl
I am a qualified AAT accountant in Newcastle upon Tyne.
Please get in touch if you’re interested in arranging an appointment.