The stock figure that never moves (and what it's hiding)

By Peter Edwards ACMA CGMA · Chartered Management Accountant in practice

There's a simple test that exposes more bad sets of books than any ratio: get two trial balances for the same business at two different dates, put them side by side, and look at stock. In a business that genuinely buys and sells goods, stock moves. It rises before busy periods, falls after them, wobbles with supplier deliveries. When the figure is identical to the penny at two dates months apart while trading carried on, nobody counted anything. The number is a plug — typed in once, probably at a year-end long past, and rolled forward ever since.

Why a plug is worse than no figure at all

A missing stock account at least announces itself — margins go obviously wrong and anyone reviewing the books sees it. A plug is camouflage. The balance sheet looks like it carries stock, the margin looks plausible in an average month, and the distortion runs silently underneath: every month, the true movement in stock — goods bought but unsold, or sold from the shelf — lands directly in profit instead. Reported profit moves pound-for-pound with a number no one can evidence. The business owner is making decisions, and possibly drawing dividends, off a P&L that is quietly wrong in both directions across the year.

Where plugs come from

• The year-end that never ended. An accountant put a counted (or estimated) figure in for statutory accounts; nobody in the business ever touched it again.
• A migration artefact. The opening balance from the old system, carried in and calcified.
• The awkward conversation nobody had. Counting stock is disruptive and unglamorous; "we'll do it at year-end" becomes never.

Detecting it in a pre-engagement review

You need exactly two documents: trial balances at two dates, ideally six to twelve months apart. Compare every balance-sheet line. Stock identical while revenue flowed is the headline finding — but run the same eye over accruals, prepayments and provisions: any of them frozen across the gap has been rolled forward without review, and the real figure is now something else. One static balance is an oversight; several is a pattern, and the pattern is the finding.

Fixing it

1. Count. A physical stocktake at a clean cut-off, valued at cost. There is no substitute and no shortcut; everything else in the correction hangs off this number.
2. Post the correction — the difference between the plug and reality goes through the P&L, dated honestly. This is the moment the accumulated distortion surfaces, and it can be large; the client should hear that from you before the numbers say it.
3. Install movement: monthly opening/closing stock journals — from counts where practical, from a defensible estimate method where not — so the figure breathes from now on.
4. Diarise the counts. A plug is a process failure, not an arithmetic one; without a standing count routine it will re-form.

In scoping terms, a stock plug converts directly into work you must price: the stocktake support, the correction, and the first months of the new routine. It is also the single best evidence to show a prospect why the engagement costs what it costs — the frozen number is on their own paper.

Related: Negative gross margin: what it actually means · How to review a client's Xero books before you quote