Short answer

Inventory records are diligence-ready when your accounting system and the physical shelf agree within a variance you can explain, tracked every month, with a written reserve policy standing behind the slow-moving stock. A buyer's count is going to find a gap. What decides whether the gap costs you money is whether you already knew it was there.

Most owners think of inventory as an operations problem. It is an operations problem, and it is also the balance sheet line most likely to move your reported earnings without anybody deciding to move them.

Book to floor variance is the number, not the count

Book to floor variance is the difference between the inventory value your accounting system says you hold and the value of what is actually on the shelf when someone counts it.

Every business that carries stock has a book to floor variance. That is not a criticism of anyone's bookkeeping. Goods get damaged, samples go out, a receipt gets entered against the wrong item, a return sits on a shelf for four months before anybody codes it. The variance is a fact of physical inventory, and pretending otherwise is what creates the problem.

The businesses that count once a year discover their variance once a year, usually in a number large enough to distort whichever month it lands in. The businesses that count a slice of the shelf every week know their variance as a percentage that drifts a little and gets investigated when it drifts a lot.

A buyer, a lender, or a quality of earnings team does not expect the variance to be zero. Any of them will react badly to a variance nobody can explain, and worse to a business that does not know what its variance is.

Four accounting decisions create most of the gap

Four routine bookkeeping choices produce the large majority of book to floor variance, and each one is a process fix rather than a systems purchase.

Receipts recorded in batches instead of at receipt. Goods arrive Monday and get entered Friday, so for four days the system and the shelf tell different stories. If the month ends on a Wednesday, that difference is now in your financial statements.

The costing method applied inconsistently. Freight and duty capitalized into the cost of some receipts and expensed on others means two identical units carry two different values. The method matters far less than the consistency, and inconsistency is what a reviewer finds.

Shrink that never gets booked. Breakage, theft, expired goods, samples pulled for a customer, units used internally. Each one leaves the shelf. If nothing leaves the ledger, the ledger is overstated by the cumulative total of every one of those events since the last physical count.

Returns and rework carried at full cost. A returned unit that cannot be resold as new is still sitting in the system at what you paid for it. Multiply by a few years of returns and the number is real.

None of the four requires new software. All four require somebody to own the transaction discipline, which is usually the actual gap.

A slow moving reserve is a policy, not a judgment call

A slow moving and obsolete inventory reserve should be governed by a written policy with a defined trigger, a defined method, and a defined review cadence, so the reserve applies itself instead of being argued about every quarter.

A policy is three decisions written down. What triggers a review, for example no unit movement over a set number of months. What the reserve is measured against, for example the difference between carrying cost and what the goods can realistically be sold for. And who reviews it and how often, which should be the same person who owns the monthly close, on a fixed cadence.

The specific thresholds are yours to set and they should reflect how your products actually behave. A building products distributor and a food brand with expiration dates should not use the same trigger.

What matters is that the policy exists in writing and gets applied the same way every period. An owner with a written policy and a reserve already sitting on the balance sheet has answered the question before it was asked. An owner without one is going to have the reserve calculated for them by somebody with a different set of incentives.

The Variance Trail Rule

Twelve consecutive monthly reconciliations of your inventory system to the general ledger, with the variance stated as a percentage of inventory value and a one-line reason for any month that moves materially against the prior three, is worth more in diligence than one perfect count.

That is the Variance Trail Rule, and it runs against most owners' instincts. The instinct is to clean everything up right before a review so the number looks right. The problem with a clean number that has no history is that a reviewer cannot tell the difference between a business with good inventory discipline and a business that scrubbed the file last week. So the reviewer tests it, which means more requests, more sampling, and more time.

A trail is testable in one pass. The reviewer looks at twelve data points, sees a variance that behaves like a real process, checks two of them, and moves on. The trend is the evidence. The single number is only a claim.

This also changes what a bad month means. A month where variance jumps and the reconciliation says why, in one line, reads as control. The same jump with no note reads as an unknown, and unknowns get priced.

Stock you hold and stock you do not

Inventory sitting somewhere you do not control still has to be reproducible from your own records on any month-end, by location, without a phone call.

Third party logistics providers, marketplace fulfillment centers, co-packers, and customer sites all hold goods that belong to you. The record requirement is a monthly report from each of them, reconciled to your ledger in the same close where you reconcile everything else. Pulling those reports for the first time during a transaction is how owners discover that one location has been off for a year.

Consignment runs the other way. Stock a vendor owns and you hold is not your asset, and the system needs to flag it so that nobody counts it as yours and nobody values it on your balance sheet. The consignment agreements belong in the same file as the inventory reports, because the exclusion has to be provable rather than asserted.

Goods in transit are decided by the shipping terms on the purchase order rather than by whether they have reached your dock. Your month-end cut-off should follow those terms. Received but not yet invoiced is the same issue seen from the payables side, and it is the version that most often turns into an unrecorded liability.

The test for all of it is simple. Pick a month-end at random and ask your books to produce inventory by location. If the answer requires three emails, the records are not ready.

What the gap actually costs, in dollars

The cost of an unmanaged inventory gap shows up as a reduction in reported earnings and as a reduction in what a buyer will pay for those earnings, and it compounds.

Here is the arithmetic, on a hypothetical business with every figure assumed purely for illustration. Assume a company carries $900,000 of inventory on the balance sheet and has never booked a slow moving reserve. Assume a review determines that $120,000 of that stock has not moved in more than two years and is realistically worth $30,000. Booking the correct reserve reduces inventory by $90,000 and reduces that period's reported earnings by the same $90,000.

That is the visible cost. The larger one is that the write-down landed in the year a buyer was reading the numbers rather than three years earlier, so it shows as a fresh loss against current earnings rather than as history. Assume the same business is being valued on a multiple of earnings. A $90,000 hit to the earnings figure a buyer is capitalizing is worth several times $90,000 in enterprise value, and the reserve was always going to be taken. The only variable was when.

Where to start if you are eighteen months out

The sequence matters more than the speed, and it runs in three stages.

Start with the reconciliation, because it costs the least and tells you the most. One month of tying your inventory system to the general ledger will tell you the size of your variance, and the size of the variance tells you whether the next stage is a cleanup or a habit.

Then write the reserve policy and take the reserve. Taking it early is the entire point. A write-down eighteen months before a process is history. The same write-down during a process is a finding.

Then build the trail. Cycle counting on a rolling schedule, monthly reconciliation as a standing close task, third party reports collected the same week every month. After twelve months you have the thing that is hardest to fake and most valuable to own, which is a documented record of how your inventory actually behaves.

The transaction side of this, meaning how the number you produce gets used in a deal, is a separate question with its own mechanics. If you want to see how a working capital target is set and what your inventory balance has to do with it, our M&A colleagues cover that in how a working capital peg is set when you sell a business at Texas Exit Advisors.

Where Thryve fits

Thryve Accounting & Advisory builds the close that makes inventory defensible: a monthly reconciliation of the inventory system to the general ledger, a written slow moving and obsolete policy with the reserve actually booked, documented costing with landed cost support, and third party reports pulled and tied every month rather than assembled under pressure.

That work does not look like exit preparation while you are doing it. It looks like a clean month-end. It becomes exit preparation the first time somebody asks your books a question you can answer in an afternoon instead of a fortnight.

If you carry inventory and cannot say what your book to floor variance was last month, that is the place to start, and it is a conversation worth having now rather than the quarter before you go to market.

Last reviewed: September 2026. This article is general information, not legal, tax, or accounting advice specific to your business. Inventory accounting policies, reserve methods, and reporting requirements vary by industry, entity, and circumstance, and inventory methods carry tax consequences that are outside the scope of this article. All dollar figures above are illustrations built on assumptions stated in the sentences that carry them. Talk to your own CPA about how any of this applies to you.

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