Inventory Observation: Standards, Planning, and Floor Procedures

Inventory observation audit procedures center on the auditor’s physical attendance at the client’s inventory count, where the auditor watches how counting is performed, runs independent test counts in both directions, captures shipping and receiving cutoff information, and inspects goods for condition. The work continues after the count, when those results get traced into the client’s final inventory compilation and reconciled to the balance sheet number. Skipping observation is not a normal option; the burden falls on the auditor to justify any audit opinion issued without it.

Which Standard Applies

For public company audits, PCAOB Auditing Standard 2510 establishes inventory observation as a generally accepted auditing procedure. An auditor who issues an opinion without performing observation bears the burden of justifying that decision.¹ For audits of nonissuers, the AICPA’s AU-C Section 501 governs and imposes requirements that parallel AS 2510 in most practical respects.²

Under both frameworks, observation gathers evidence for two primary financial statement assertions. Existence means the inventory recorded in the books is physically present. Completeness means every item on the warehouse floor is captured in the count records. Handling and inspecting goods also feeds the valuation assertion, because damage, spoilage, and obsolescence become visible in ways no spreadsheet reveals.

Planning Before Count Day

The count itself might take a single day, but the preparation determines whether observation produces useful evidence. The auditor reviews the client’s written counting instructions before the count date. Those instructions should specify how to identify and segregate damaged goods, consignment inventory, and items belonging to third parties. Weak instructions are a red flag; if the client has not thought through partially counted areas or count-tag control, the auditor needs to push for changes before the day arrives.

Risk assessment drives sample selection. The auditor identifies inventory categories with the highest dollar value, the most historical count discrepancies, or the greatest susceptibility to theft and obsolescence, and those categories get heavier test-count coverage. Location selection follows the same logic, mixing the main warehouse with remote or off-site storage so no material segment is left unseen. AS 2510 requires the auditor to be present at the time of the count and to satisfy themselves about the effectiveness of the counting methods, so planning pins down when, where, and with how many staff that presence will happen.¹

Before the count begins, the auditor confirms that the client has a documented cutoff system in place for shipping and receiving. Without one, there is no clean way to determine which goods were in the building at the count moment and which had already left or not yet arrived.

Procedures On the Floor

Once counting starts, the auditor is not a passive observer. The core procedure is independent test counts, and those counts run in two directions.

The first direction starts with physical items. The auditor selects goods on the warehouse floor and traces them to the client’s count sheets. If an item is present but does not appear on the sheet, the count has a completeness problem. The second direction reverses that. The auditor picks tag numbers or line items from the count records and walks the floor to find the corresponding inventory. If a tag lists 200 units but only 150 can be located, that is an existence problem. Both directions get documented in the working papers with item descriptions, locations, and verified quantities.

Discrepancies get raised immediately with the client’s count supervisor. The point is not to note the error quietly for later; it is to get a recount and a corrected record while the team is still on the floor and the inventory has not moved.

Cutoff Testing

A lot of inventory misstatements hide in cutoff. The auditor records the serial numbers of the last shipping and receiving documents processed before the count is finalized. Those numbers create a bright line: everything shipped under those document numbers left the building and should not be included in the physical count, while everything received under those numbers should be. After the count, those document numbers get compared against the sales and purchase journals to confirm transactions were recorded in the correct period. A sale booked in December for goods that did not leave the building until January overstates cost of goods sold and understates ending inventory, or the reverse, depending on the direction of the error.

Condition and Fraud Observation

Walking the floor reveals condition problems: rusted parts, expired packaging, unsold seasonal merchandise collecting dust. Under ASC 330, inventory must be carried at the lower of cost or net realizable value, so goods that cannot be sold for what the books say they are worth may need a write-down.

Physical counts are one of the few audit procedures where fraud can be visible in real time. Empty boxes stacked to look full, areas of the warehouse the client steers the auditor away from, or counting teams that record numbers without actually counting are all warning signs. In the data, abrupt swings in inventory during peak periods, frequent write-offs management cannot explain, and large amounts of aged or unsellable inventory carried at full value all suggest the recorded balance may not reflect reality. PCAOB inspectors have specifically flagged engagements where audit teams failed to investigate discrepancies between physical counts and recorded data.³

Work-in-Process

Finished goods are relatively straightforward to count. Work-in-process is not. A partially assembled product does not lend itself to a simple unit count because the auditor also needs to assess how far along it is in production. WIP valuation typically includes raw materials consumed so far, labor hours invested, and a share of manufacturing overhead. The auditor evaluates whether management’s estimate of completion looks reasonable based on what is physically visible. A product management calls 80% complete but missing most of its components warrants further inquiry. This is inherently judgmental, which is why many manufacturers deliberately minimize WIP levels before a count date. Discussing completion stage with production floor supervisors, comparing those assessments against cost records, and noting items where the physical state contradicts the recorded percentage all become critical evidence for subsequent valuation testing.

Work That Continues After the Count

The physical count produces raw data. Converting that into reliable audit evidence happens afterward. The auditor traces test count results to the client’s final inventory compilation, the document that becomes the basis for the balance sheet number. If the compilation does not match what the auditor counted on the floor, there is either an unexplained adjustment or an error that needs investigation.

The auditor also evaluates any adjustments the client made between the physical count and the final listing. Companies routinely book adjustments for count errors, damaged goods identified later, or timing differences in receiving. Each adjustment should have documentation and a reasonable explanation. Large unexplained adjustments are a red flag for manipulation. Cutoff document numbers captured on count day get carried into this phase and matched against the sales and purchase journals.

When the Count Isn’t On the Balance Sheet Date

Companies do not always count inventory on the last day of their fiscal year. AS 2510 allows the count to happen “within a reasonable time before or after the balance-sheet date” as long as the auditor is present and satisfied with the counting methods.¹

When there is a gap between the count date and year-end, the auditor tests the transactions that occurred during that gap. If the count happened in November and the fiscal year ends in December, the auditor traces purchases, sales, and other inventory movements during December to reconcile the count results to the year-end balance. The standard specifically requires the auditor to apply appropriate tests of intervening transactions and to inspect the records of the client’s count procedures on which the year-end balance is based.¹

Recent PCAOB inspection findings identified engagement teams that “did not perform appropriate procedures to test inventory movement between the interim date and period-end date when the physical inventory observation is as of the interim date.”³

Cycle Counting and Perpetual Systems

Not every company shuts down operations for a wall-to-wall annual count. Companies with well-maintained perpetual inventory records often use cycle counting instead, rotating through different segments during the year. AS 2510 accommodates this but imposes conditions. When a company maintains reliable perpetual records that are periodically compared against physical counts, the auditor’s observation can be performed during or after the end of the audit period rather than at a single count date.¹

Some companies go further, using statistical sampling or other controls reliable enough to make a complete annual count unnecessary. The auditor can accept this approach only after confirming that the client’s procedures produce results substantially the same as a full annual count. The auditor still must be present to observe counts as deemed necessary and must verify the effectiveness of the counting procedures. Where statistical sampling is used, the auditor must be satisfied that the sampling plan is reasonable, statistically valid, properly applied, and produces reasonable results.¹

The bar is high. PCAOB inspectors flagged cases where audit teams relied on a client’s cycle count program without obtaining sufficient evidence that the procedures were reliable enough to substitute for a full physical count.³

Inventory Held Off-Site or by Third Parties

Inventory stored in public warehouses, with consignment partners, or at other off-site locations creates a physical distance problem. The auditor cannot always visit every location. AS 2510 uses a tiered approach based on materiality.

The starting point is obtaining direct written confirmation from the custodian of the quantities held. For engagements where the off-site amount is not a large share of total assets, that confirmation alone may provide adequate evidence.¹

When the off-site inventory represents a significant proportion of current or total assets, confirmation alone is not enough. The standard requires the auditor to apply one or more additional procedures:

Review the client’s procedures for evaluating the warehouse operator’s performance and reliability.
Obtain an independent accountant’s report on the warehouse operator’s controls over custody of goods (commonly a SOC 1 report), or perform alternative procedures at the warehouse to verify the reliability of information received.
Visit the location and observe a physical count of the goods, if practicable.
Confirm with lenders the details of any warehouse receipts that have been pledged as loan collateral.

The choice among these procedures depends on the auditor’s risk assessment. A highly material off-site balance with a custodian the auditor has never evaluated will typically warrant more extensive work than a long-standing warehouse relationship with a clean controls report.¹

When the Auditor Cannot Attend the Count

Sometimes the auditor is engaged after the client has already completed its physical count, or circumstances make attendance genuinely impossible. AS 2510 does not permit skipping observation and moving on. Testing accounting records alone is never sufficient to satisfy the auditor about inventory quantities.¹

The auditor must make or observe some physical counts and test the transactions that occurred between the original count date and the balance sheet date. That is paired with inspection of the client’s count records: instructions, completed tags and sheets, reconciliation reports, and any booked adjustments. Well-maintained perpetual records combined with periodic physical checks may give the auditor more flexibility on timing, but some physical verification is still required.

Where an auditor is engaged for a period in which no count was observed, such as auditing prior-year financial statements, the standard allows satisfaction through alternative procedures like testing prior transactions, reviewing records of prior counts, and applying gross profit tests, but only if the auditor has already been able to verify the current year’s inventory.¹

If none of these alternatives produces sufficient evidence, the auditor faces a scope limitation. The consequences range from a qualified opinion to a disclaimer, depending on how material inventory is to the financial statements as a whole.

Where Audits Commonly Fall Short

PCAOB inspection reports show where inventory work consistently breaks down. The following deficiencies appeared in recent findings:

Failing to test the accuracy and completeness of the period-end inventory listing reports or the completeness of physical inventory adjustments used in existence testing.
Skipping roll-forward procedures when observation occurred at an interim date rather than year-end.
Not testing the pricing of aged inventory or evaluating management’s assessment and accounting for it.
Relying on the client’s cycle count procedures without obtaining enough evidence that those procedures were reliable enough to substitute for a full count.
Performing no testing at all of whether inventory was recorded at the lower of cost or net realizable value.
Limiting procedures to reviewing the client’s own inventory reconciliation rather than performing independent substantive tests of completeness, existence, and valuation.

These findings repeat across inspection cycles, which suggests they reflect systemic weaknesses in how firms staff and execute inventory work rather than isolated mistakes.³

1
Public Company Accounting Oversight Board. AS 2510 Auditing Inventories
2
AICPA & CIMA. Statements on Auditing Standards Currently Effective
3
Public Company Accounting Oversight Board. Staff Update on 2024 Inspection Activities Spotlight