10 Common Pitfalls When a Non-Finance Person Does the Company Accounts
Many UK small businesses start with the founder, a family member or an office manager keeping the books. Cloud software makes it look easy. But the costliest errors we see are not data entry slips. They are gaps in knowledge about tax, law and accounting principles that software cannot fill.
Here are the ten pitfalls we fix most often.
1. Mixing personal and business money
Paying personal bills from the company account, or business costs from a personal card, blurs the records. For a limited company, it also creates a director's loan account. If that loan is still overdrawn nine months and one day after the year-end, the company pays a temporary tax charge of 33.75% of the balance under section 455. Large interest-free loans can also create a taxable benefit in kind.
2. Recording cash, not what was earned and owed
Company accounts are prepared on an accruals basis. Income belongs to the period the work was done, and costs to the period they were incurred. Bookkeeping straight from the bank statement misses unpaid invoices, accruals and prepayments, so monthly profit swings wildly and year-end figures are wrong.
3. Expensing assets (or capitalising expenses)
A new laptop or van is a fixed asset, not an expense in the accounts, even when the Annual Investment Allowance gives full tax relief. Mixing the two distorts profit, the balance sheet and your tax computation. The opposite mistake, capitalising repairs, inflates assets.
4. VAT errors
VAT is where small errors become expensive. Common problems include:
- Missing the £90,000 registration threshold, which is a rolling 12-month test, not a tax year test.
- Reclaiming input VAT without a valid VAT invoice.
- Forgetting the reverse charge on services bought from overseas suppliers or under the construction industry rules.
- Staying on the Flat Rate Scheme when it no longer saves money.
HMRC can charge penalties and interest on errors, even honest ones.
5. Skipping bank reconciliations
If the bank balance in your software does not match the actual statement, every report built on it is wrong. Duplicate transactions, missed payments and bank feed errors pile up quietly until year-end, when they are slow and costly to untangle.
6. Payroll and employment status mistakes
PAYE must be reported to HMRC through Real Time Information on or before each payday. Auto-enrolment pension duties apply once staff qualify. Treating someone as a self-employed contractor when they are really an employee, or ignoring IR35 for personal service contractors, can lead to backdated tax, National Insurance and penalties.
7. Paying dividends without the profits to cover them
Dividends can only be paid from distributable reserves. Paying them from cash alone, when the company has accumulated losses, makes them unlawful. Directors may have to repay them, and HMRC may treat them as salary or loans instead.
8. Missing statutory deadlines
| Obligation | Deadline (private company) |
|---|---|
| Corporation tax payment (most companies) | 9 months and 1 day after year-end |
| Annual accounts to Companies House | 9 months after year-end |
| Corporation tax return (CT600) | 12 months after year-end |
| Confirmation statement | At least once every 12 months |
| VAT return and payment | 1 month and 7 days after the period end |
9. Not preparing for Making Tax Digital
Since 6 April 2026, sole traders and landlords with qualifying income over £50,000 must keep digital records and send quarterly updates to HMRC. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028. Spreadsheets kept "for the accountant at year-end" no longer meet the rules.
10. Bookkeeping that never becomes management information
The biggest hidden cost is lost insight. Without monthly management accounts, cash-flow forecasts and margin analysis, owners make pricing, hiring and borrowing decisions blind.
Correct records are the minimum; useful information is the goal.
Why these mistakes keep happening
None of these errors comes from carelessness. They come from asking someone to apply tax law, company law and accounting standards without the training to do so. Software automates entries, but it cannot judge whether a payment is a dividend, a loan or a salary.
How Step 1 Advisors can help
You do not need a full in-house finance team to get this right. Our remote accounting service keeps your books, VAT and payroll accurate every month, and our fractional CFO service turns those numbers into decisions. If you are cleaning up after a year of DIY bookkeeping, we can review, correct and bring you up to date.
Worried about your books? [Book a free bookkeeping health check with Step 1 Advisors.]→