We see a lot of small business books. Clean ones, neglected ones, and the particular kind that look immaculate on screen while being quietly, expensively wrong underneath.
These are the seven errors we encounter most often. None of them is exotic. All of them cost real money — in overpaid tax, underpriced products, missed cash, or decisions made on numbers that were never true.
1. Recording e-commerce and card payouts as net deposits
This is the single most common material error in modern small business books, and it is worth putting first because almost every online business has it.
When Stripe, Shopify, PayPal, Square or Amazon pay you, the deposit hitting your bank is net. It is gross sales, minus platform fees, minus refunds, minus chargebacks, sometimes minus a rolling reserve, occasionally spanning two different months.
Recording that single deposit as "sales" does three things at once:
- Understates revenue — your actual turnover is higher than your books say, which matters for lending, valuation and sometimes registration thresholds.
- Hides your fee cost entirely — we regularly find businesses paying five figures a year in processing fees they have literally never seen as a line item.
- Destroys margin analysis — you cannot know your real gross margin if both revenue and cost of sale are wrong.
The fix: each processor gets its own clearing account in your books. Gross sales go in, fees and refunds come out, and the net payout is what transfers to your bank account. The clearing account is then reconciled monthly against the processor's own statement. It is the core of our e-commerce bookkeeping work. For the step-by-step method with a worked example, see how to reconcile Shopify payouts.
2. Never reconciling the balance sheet control accounts
Most small business owners look at the profit and loss because profit is what they care about. Almost nobody reads the balance sheet. That is exactly why the balance sheet is where the errors live.
The key check is simple: your aged debtor report total must equal the receivables figure on the balance sheet, and the same for creditors. If they differ, someone has posted a journal or a payment directly to the control account, and something is wrong.
We routinely open files where these have not agreed for two or three years. By that point the difference is a five-figure number nobody can explain, and untangling it costs far more than the five minutes a month it would have taken to catch.
Profit and loss errors get noticed because people read the P&L. Balance sheet errors compound for years because nobody does.
3. Posting loan repayments entirely to expense
A loan repayment is two different things in one payment: interest, which is an expense, and principal, which reduces a liability on the balance sheet.
Coding the whole payment to an expense account overstates your costs, understates your profit, and leaves the loan sitting on your balance sheet at its original value forever. We have seen balance sheets showing loans that were fully repaid three years earlier.
The fix: get the amortisation schedule from your lender and split each payment. If you cannot get one, at minimum reconcile the loan balance to the lender's statement at each year end and correct the difference through interest.
The same logic applies to equipment finance, hire purchase and vehicle leases — each has a capital and an interest element, and lumping them together distorts both your profit and your assets.
4. Expensing assets and capitalising expenses
Buy a £4,000 machine and post it to "equipment expense", and that month looks catastrophic while every following month looks artificially good. Your balance sheet also shows no asset you actually own.
The reverse happens too: routine repairs capitalised as improvements, inflating assets and depressing legitimate current-year costs.
The fix: agree a capitalisation threshold with your accountant — a common figure is anything over £500 or $500 with a useful life beyond a year — write it down, and apply it consistently. Consistency matters more than where exactly you draw the line.
5. Treating sales tax and VAT collected as income
Sales tax, VAT and GST that you collect from customers is not your money. You are holding it on behalf of the tax authority.
When it is recorded as revenue rather than as a liability, two bad things happen. Your turnover looks higher than it is, and — far more dangerously — the money looks spendable. Businesses get into genuine trouble spending tax they were holding in trust, because the bank balance never distinguished it.
The fix: tax collected sits in a liability account and clears when you pay the return. Reconcile that account every period. If the balance does not match what you expect to owe, something is miscoded.
6. Letting the chart of accounts sprawl
This one looks harmless and is quietly corrosive. Somebody cannot find the right category, so they create a new one. Repeat over two years and you have 180 accounts including "Software", "Software & Subscriptions", "SaaS", "Online tools" and "Subscriptions".
Your spend on software is now split five ways. No report shows what you actually spend. No month compares to another. Anything you might have noticed — a tool nobody uses renewing at £300 a month — is invisible.
The fix: a small, deliberate chart of accounts. Most businesses under $5m need 40–70 accounts, not 200. If you want more granularity, use tracking categories or classes rather than multiplying accounts. And lock down who can create new ones.
7. Never looking at comparatives
A single month's P&L in isolation is nearly meaningless. Revenue of $84,000 is either excellent or alarming depending entirely on what the last six months looked like.
Running every report with prior-month and prior-year columns is free, takes one extra click, and is the fastest error-detection tool in bookkeeping. Costs that doubled, revenue that halved, a margin that moved three points — these jump off a comparative report and are completely invisible on a standalone one.
Roughly half the bookkeeping errors we catch each month are caught this way, before anyone has audited anything. Something simply looks wrong, so we go and look.
The honourable mention: mixing personal and business
The famous one, and it genuinely is a problem — it makes bookkeeping slower, muddies the audit trail, and in some structures can weaken the legal separation between you and the company.
But we rank it eighth deliberately. It is annoying and it costs you in bookkeeping hours. The seven above cost you in wrong decisions, and that is a bigger number.
How to check your own books tonight
Four checks, about fifteen minutes:
- Does your aged debtor total equal the balance sheet receivables figure? If not, something is posted directly to the control account.
- Does every loan on your balance sheet match the lender's current statement? If not, repayments are being split wrongly or not at all.
- Open your chart of accounts and count. Over 120 accounts for a business under $5m usually means sprawl.
- Run last month's P&L with a prior-year column. Anything that moved more than 30% — can you explain it in one sentence?
If any of those makes you uneasy, that is genuinely useful information rather than a reason to panic. Every one of these is fixable, and fixing them is considerably cheaper than continuing to make decisions on numbers that are not true.
Written by Pro Bookkeepers and reviewed by an ACCA-qualified accountant. General guidance only, not tax or accounting advice for your specific circumstances — speak to a professional who knows your business and jurisdiction.