Interim Inventory Counts: Roll-Forward and Roll-Back Procedures With a Worked Calculation

Clients with perpetual records often count inventory at an interim date, a month or two before year end, or in the weeks after year end. The auditor attends that count, then has to prove what the balance was at the balance sheet date. The bridge from the count date to the balance sheet date is the roll-forward (or roll-back, if the count was after year end). It is a calculation backed by evidence on every line. This post sets out the method. For the attendance itself see inventory observation.

What the standard needs

If inventory is material, the auditor attends the count where practicable to evaluate management's instructions, observe the count, inspect the inventory and perform test counts, and tests the final inventory records against the count results. When the count is on a date other than the balance sheet date, the auditor also obtains evidence that changes in inventory between the count date and the balance sheet date are properly recorded. The GAO Financial Audit Manual makes the same point for interim testing generally: because the report covers the balance sheet date, not the interim test date, further substantive procedures must cover the remaining period, and analytical procedures comparing roll-forward activity by month can support them.

The bridge

The calculation starts with the count-date inventory per the perpetual or the adjusted count, and moves to the balance sheet date.

Roll-forward (count before year end):

Inventory at count date, as counted and valued

• Purchases received between count date and year end
  − Cost of goods sold between count date and year end
  ± Other movements (transfers, adjustments, scrap, returns to vendors)
  = Inventory at balance sheet date, to compare with the ledger

Roll-back (count after year end):

Inventory at count date
− Purchases received between year end and the count date

• Cost of goods sold between year end and the count date
  ∓ Other movements
  = Inventory at balance sheet date

Worked example: roll-forward

A client counts on November 20. Year end is December 31. Illustrative amounts:

The difference of $26,000 is 0.8 percent of the balance. Whether it matters depends on materiality, but it must be investigated.

Evidence for each line

The count-date balance. Use the counted quantities, priced and extended, and reconcile to the perpetual at the count date. Differences between count and perpetual should have been posted by the client. If the client posted a count adjustment later, test that entry and its timing.

Purchases received in the interval. Test the receiving reports and the purchase journal for the interval. Select receipts and agree to vendor invoices and to the quantity and cost. Include goods in transit under the proper shipping terms. Test cutoff at year end: last receiving report numbers and the purchases recorded around the date. See cutoff testing.

Cost of goods sold in the interval. The cost relieved must match what shipped. Select shipments and trace to the invoice, the shipping document and the cost relieved from inventory. Compare gross margin by month in the interval with the margin before and after for reasonableness. Under-relieved costs overstate inventory.

Other movements. Transfers between locations, scrap, returns to vendors, consignments in and out and manual adjustments. These are the lines where errors and management intervention concentrate. Test all that are significant, and examine the support and approval.

The ledger and perpetual at year end. After the roll-forward, compare the computed amount to the year-end ledger. Investigate differences, which may reflect unrecorded transactions, improper cutoff or posting errors.

Roll-back example

A client counts on January 6. Year end is December 31. Illustrative amounts:

The roll-back adds cost of goods sold shipped in the first week of January, because those goods were on hand at year end, and removes purchases received after year end. Test the shipping records for January 1 to 6, and confirm that shipments after year end are not already relieved from the December 31 balance.

Red flags

• A gap between the count date and the perpetual update. A client that posts count adjustments weeks later is not controlling the interval.
• Large manual adjustments or reversals in the interval.
• Margins that drop in the interval, which suggests costs relieved on goods not sold, or rise, which suggests inventory left on the books.
• Unusual receipts of goods near year end from related parties.
• Shipping or receiving cutoff that is not documented.
• Different cost methods applied before and after the count date.
• A count at a location where the auditor did not attend and the roll-forward covers it.

When the roll-forward fails

If the computed balance and the ledger differ by more than tolerable, the auditor investigates and proposes an adjustment. If the cause cannot be found, expand the testing of the interval, or perform a count at year end. If sufficient evidence cannot be obtained and the effect is material, the opinion is affected. If the auditor cannot attend the count because of unforeseen circumstances, the auditor makes or observes some counts on an alternative date and tests the intervening transactions. Where attendance is impracticable, the auditor considers whether alternative procedures give sufficient appropriate evidence.

Controls and assurance

The roll-forward is only as good as the perpetual system and the controls over movement. If the client has strong controls over receiving, shipping and cost relief, the auditor can test controls and reduce the extent of detail testing. If not, the detail work grows. A limited interval, a month or less, with a reliable perpetual is far easier than a quarter with weak controls.

Documentation

• Count date, location, observation workpaper and test counts.
• Bridge with each line, evidence and the tie to the ledger.
• Testing of receipts, cost of sales and other movements.
• Cutoff documentation at the balance sheet date.
• Differences investigated, entries proposed.
• Conclusion on inventory at the balance sheet date.

CORAA prepares ready-to-review audit files for US CPA firms; the firm keeps the client, the review and the signature. See /us.

Sources

• AICPA, AU-C Section 501, Audit Evidence: Specific Considerations for Selected Items (inventory)
• AICPA, AU-C Section 330, Performing Audit Procedures in Response to Assessed Risks and Evaluating the Audit Evidence Obtained
• U.S. Government Accountability Office, Financial Audit Manual, Volume 1 (GAO-26-108577), June 2026, sections 295 D and 495 C on interim testing and the roll-forward period: gao.gov
• Australian Auditing and Assurance Standards Board, ASA 501, which follows ISA 501 (counts on a date other than the reporting date; unforeseen inability to attend): standards.auasb.gov.au

AU-C references are to AICPA Professional Standards, paraphrased here; read the standard itself before relying on a requirement. This page is guidance, not professional advice. Report an error