Inventory in FDD: ageing, obsolescence, provisioning adequacy, valuation methods and pre-sale manipulation risks, and how each one hits the NWC peg and EBITDA.
For any manufacturer, distributor or retailer, inventory is usually the largest line in working capital — and the easiest to dress up. A warehouse full of stock looks like value on the balance sheet, but a buyer needs to know how much of it will actually sell, at what price, and how much has quietly become unsellable. Inventory is where balance sheet quality and working capital meet, and it is one of the line items a vendor is most tempted to manage in the run-up to a sale. A diligence analyst who knows where to look here protects the buyer from paying for stock that should have been written off years ago — and, just as often, from crediting the seller at completion for value that will never convert to cash.
Inventory wears two hats in diligence. As a working capital item it ties up cash, feeds the completion mechanism and drives the working capital target. As a balance sheet quality item — squarely in the territory of a quality-of-net-assets review — it raises the question of whether the carrying value is supportable, whether the stock is really worth what the accounts say.
The two interact. If inventory is overstated (under-provided), working capital looks artificially healthy and the asset is carried above its real value. Both effects flatter the seller's position, which is exactly why inventory deserves dedicated scrutiny rather than a glance.
Inventory is the only line that simultaneously inflates the balance sheet, the working-capital peg and — through cost of sales — reported EBITDA. Get it wrong and you feed an error into three parts of the deal at once.
The first thing the analyst pulls is an ageing profile: how long each line of stock has been sitting. Slow-moving and aged inventory is the leading indicator of an obsolescence problem.
The analyst is testing one thing: will this stock convert to cash at or above its carrying value, or has the business simply declined to face up to writing it down?
Once ageing exposes the problem stock, the question becomes whether the provision against it is adequate. This is the heart of inventory quality work.
Under-provisioning is the single most common inventory finding, and the most consequential, because it props up both the asset and the earnings.
Suppose the target carries £8.0m of finished-goods inventory and a £0.4m obsolescence provision. Your ageing analysis, benchmarked to the actual recovery rate the business has historically achieved on old stock, looks like this:
| Ageing bucket | Carrying value (£m) | Realisation rate | Realisable value (£m) |
|---|---|---|---|
| 0–90 days | 5.0 | 100% | 5.0 |
| 90–180 days | 1.5 | 90% | 1.35 |
| 180–365 days | 1.0 | 60% | 0.6 |
| Over 1 year | 0.5 | 20% | 0.1 |
| Total | 8.0 | 7.05 |
Realisable value is £7.05m against a carrying value of £8.0m — a shortfall of £0.95m. The book provision is only £0.4m, so the provision is understated by £0.55m. That half-million is a real adjustment: it comes off net assets, and depending on its nature it will move either the working-capital peg or normalised EBITDA. Notice the discipline — the realisation rates are anchored to the company's own recovery history, not plucked from the air, because a finding you cannot evidence is one you cannot defend in a negotiation.
How inventory is valued changes its carrying amount, so the analyst must understand the policy and check it has been applied consistently.
| Method | How it values stock | Diligence watch-point |
|---|---|---|
| FIFO (first in, first out) | Oldest costs expensed first; closing stock at recent costs | In rising-cost periods, inflates margin and inventory value |
| Weighted average | Blended average cost across units | Smooths cost swings; check the averaging is applied correctly |
| Standard costing | Stock at predetermined standard costs, with variances | The variances are the risk — see below |
Standard costing variances deserve special attention. When a business values stock at standard cost, the difference between standard and actual cost piles up as a variance. If favourable variances are capitalised into inventory rather than expensed, or unfavourable variances are deferred rather than recognised, the result is overstated stock and flattered margins. The analyst should trace how variances are treated and whether material balances are sitting in inventory that ought to have hit the P&L. A related trap is overhead absorption: capitalising too great a share of fixed overhead into unit cost lifts both the asset and reported margin, and reverses painfully once volumes fall.
Inventory is fertile ground for pre-sale window-dressing, which is why it overlaps so heavily with red flags work. Common manoeuvres:
A useful tell: inventory that builds materially faster than sales in the periods leading up to a transaction. The analyst should always reconcile movements to a physical stock-take where possible, and corroborate quantities and condition rather than accept the ledger at face value.
Physical verification deserves more weight than candidates usually give it. A great deal of inventory diligence is done from schedules in the data room, but the schedules describe stock the analyst has never seen. Where the deal warrants it — and where inventory is the dominant working-capital line — attending or reviewing the year-end stock-count, sampling high-value lines, and inspecting the physical condition of the oldest stock is worth far more than another pivot table. Obsolete stock rarely announces itself in a spreadsheet; it announces itself as dusty pallets in the corner of the warehouse that no one has touched in eighteen months. This is one of the few areas of financial diligence where getting out from behind the screen genuinely changes the answer.
Inventory findings land in two places, and keeping them separate matters.
On working capital: overstated or aged inventory must be normalised before setting the working capital target — the peg. If the seller's recent balance sheets carry inflated stock, the buyer does not want that inflated level baked into the completion peg, because at completion the buyer would otherwise be crediting the seller for stock that is not really there. The analyst normalises inventory to a supportable, representative level so the true-up at completion is fair.
On EBITDA: where under-provisioning or variance manipulation has flattered earnings, the analyst removes the benefit from normalised EBITDA. A provision release that boosted last year's profit is a non-recurring, non-trading benefit and comes out of the run-rate — the same EBITDA-adjustment logic applied to any timing distortion.
Crucially, the analyst must avoid double-counting. A one-off catch-up write-down is a balance-sheet / net-debt-style adjustment; a recurring policy understatement normalises both EBITDA and the working capital target. Allocating each finding to the right place, once, is the mark of a careful analyst.
It helps to think through the sequence explicitly. First, establish the supportable carrying value using net-realisable-value testing anchored to actual recovery history. Second, ask whether the gap between reported and supportable value arose in a single period (a catch-up) or accumulated because policy has been persistently too generous (a run-rate issue). A catch-up is a discrete hit to net assets that a buyer will press to have reflected in the price, much like any other overstated asset in a balance-sheet-quality review. A run-rate understatement is different: it means every year's cost of sales has been too low, so both the sustainable EBITDA and the level of inventory the business genuinely needs are misstated. Treating those two cases identically is the single most common inventory error juniors make, and it either double-charges the seller or lets a recurring problem slip through the peg entirely.
A typical prompt: "Inventory has grown 40% while revenue is flat, and the obsolescence provision has fallen. What do you make of it?"
A strong answer reads the signal and traces it to price: "That combination is a red flag for pre-sale window-dressing. Stock building far ahead of flat sales suggests either over-purchasing or unsellable inventory accumulating, and a falling provision against a growing, ageing book is the opposite of what I'd expect. I'd pull the ageing and turnover trends, check last-movement dates for the oldest lines, and test net realisable value against carrying cost — anchoring my realisation rates to the company's actual recovery history. If the provision is understated, I'd quantify the shortfall and split it: any release that flattered earnings comes out of normalised EBITDA, and I'd normalise inventory down to a supportable level before setting the working-capital peg, so the buyer isn't crediting the seller for stock that won't convert to cash. I'd be careful not to double-count a one-off catch-up against the recurring policy effect, and I'd want to corroborate the closing quantities against a physical stock-take rather than trusting the ledger."*
That answer shows the interviewer you can spot manipulation, corroborate it, and translate it into both the EBITDA bridge and the working capital mechanism — the integrated reasoning TS interviewers are looking for.
Inventory is deceptively simple — a pile of stock, a single number in the accounts — and precisely because it looks simple it is where the least disciplined analysts wave through the biggest errors. The stock that never sells, the provision that quietly shrinks, the overhead absorbed a little too generously: each one feeds the balance sheet, the peg and the margin at the same time. Learn to trace a line of ageing stock through to a net-realisable-value write-down, then split that write-down correctly between the working-capital peg and the EBITDA bridge, and you protect the buyer from paying twice for stock that should have been scrapped. That is the analyst every deal team wants in the warehouse.
The Transaction Services Interview Programme (€119.99, one-time) includes a full inventory module — ageing and obsolescence analysis, net-realisable-value testing, costing and variance traps, and how findings flow into the working capital peg and the EBITDA bridge, worked through on real stock schedules. Enrol today.
Hundreds of candidates prepared their interviews with this programme. Those who landed the role have one thing in common: they worked the cases before walking into the room.
