Legally, a UK sole trader and their business are the same person. There's no rule that says you must have a separate business bank account, and plenty of sole traders run everything — customer payments, the mortgage, materials, the weekly shop — through one personal account. It works right up until January, when you (or your accountant, at your expense) have to go through twelve months of statements deciding, line by line, whether each transaction was business or life. Separating business and personal money isn't a legal requirement; it's a kindness to your future self.
Why one account makes January miserable
The problem with a mixed account isn't storage — the bank keeps the statements either way. It's that every line needs a decision, and you're making those decisions months after the fact. Was that £64 at B&Q for the job on Weaver Street or for your own bathroom? Was the fuel that week business miles or the school run? Is that £250 transfer in a customer payment or your mate paying you back?
Multiply that by a thousand-odd transactions a year and you get the January ritual: a weekend lost to bank statements, a stack of maybes, and numbers that are ultimately guesses. Guessed expenses cut both ways — claim too much and you've got a problem if HMRC ever looks closely; claim too little (far more common, because forgotten expenses default to 'personal') and you quietly overpay tax. If an accountant does the untangling instead, you're paying professional rates for sorting, not advice.
HMRC requires sole traders to keep records of business income and expenses for self-assessment, and to keep them for at least five years after the 31 January submission deadline for the relevant tax year. A mixed account doesn't breach that — but it makes demonstrating it painful.
The two-account setup
The fix is almost embarrassingly simple, and you can do it this week:
- Open a second account used only for business. As a sole trader this can be a dedicated business account or, with some banks, simply a second current account you reserve for trade (check your bank's terms — some don't allow business use of personal accounts). What matters is the discipline, not the label.
- Point all business income at it. Every invoice, every customer transfer, every card payment lands there. Nowhere else.
- Pay all business costs from it. Materials, fuel for work, tools, insurance, phone if it's a business line — from the business account, every time.
- Pay yourself on purpose. Move a regular amount — weekly or monthly — to your personal account, and live out of the personal one. That transfer is your 'wages' (drawings, formally), and it's the only regular traffic between the two.
Many sole traders add a third pot: a tax set-aside, skimming 20 to 30 per cent of income as it arrives so the January and July payments are already sitting there. The right percentage depends on your profit and circumstances — a question worth putting to an accountant once a year.
Now look at what January becomes. Business account: everything in it is business. Personal account: none of your accountant's concern. The line-by-line archaeology disappears, because the sorting happened all year, one transaction at a time, at the moment you chose which card to use.
The split is only as clean as your capture habits
Two accounts sort the money, but they don't record what the money was for. A £180 card payment to a merchant on the business account is obviously business — but which job? Claimable against what? And two categories of expense never touch the business account at all:
- Cash and wrong-card purchases. You will sometimes pay for business items in cash or on the personal card by accident. Without a receipt captured at the time, those expenses evaporate.
- Mileage. If you claim HMRC's approved mileage rates — 45p a mile for the first 10,000 business miles in a tax year, 25p after that — no bank account anywhere records your miles. Only a log kept on the day does that, and for anyone who drives for work it's routinely one of the biggest claims of the year.
So the two-account setup needs a capture habit alongside it: photograph receipts when you're handed them, log miles when you drive them, note which job an expense belongs to while you still remember. The tool matters less than the friction — if capturing a receipt takes more than thirty seconds, it won't happen on a busy day. That's the thinking behind GraftG, launching soon from Green & Home Ltd: you text receipts, mileage and job notes to one WhatsApp number, and they're logged — no app, no dashboard, no evening admin session. It's the same at-source principle we describe in sole trader admin in one hour a week: capture in the moment, and the weekly tidy-up shrinks to minutes.
What your accountant actually needs
Strip away the mystique and a sole trader's accountant needs a fairly short list at year end:
- Business income for the year — which, with a clean business account, is simply what came in.
- Business expenses, by category (materials, motor costs, tools, insurance, phone, and so on), with receipts to back them up.
- A mileage log, if you're claiming mileage rather than actual vehicle costs.
- Notes on anything mixed-use — the van, the phone, working from home — so the business proportion can be worked out properly.
Hand that over as organised records and you're paying your accountant to advise — on allowances, on timing, on whether your set-aside percentage is right — rather than to sort. Hand over a shoebox and a mixed statement and you're paying them to do the January misery for you, at their hourly rate. (And as with everything here: this is general guidance, not tax advice — your own numbers deserve a conversation with a professional.)
The whole thing compounds. Two accounts split the money. At-source capture records the why. Your accountant gets a clean file, HMRC's record-keeping rules are comfortably met, and next January is an afternoon, not a lost weekend.
GraftG is built to keep the split clean without the evening admin: receipts, mileage, quotes, invoices and job records, all by texting one WhatsApp number. Your admin sorted. Just WhatsApp it. Launching soon — join the waitlist at graftg.co.uk.