Inventory accounting is how a product business values and reports the stock it holds. It drives cost of goods sold, gross margin, and the tax return. The rules apply whether a business sells in one state or across several. This article is general information, not tax advice for a specific situation.
Table of Contents
- What is inventory accounting and why does it matter to a product business?
- What are the main types of inventory in accounting?
- How do you calculate beginning and ending inventory?
- Which inventory costing method should you use — FIFO, LIFO, weighted average, or specific identification?
- What is the difference between periodic and perpetual inventory systems?
- When does inventory become yours — and how do shipping terms and consignment change the books?
- How does multi-state sales tax connect to inventory accounting?
- Key Takeaways
- References
What is inventory accounting and why does it matter to a product business?
Inventory accounting is the practice of valuing and reporting on the physical inventory a business holds, according to Unleashed. Inventory sits on the balance sheet as a current asset because a company usually intends to sell finished products within a fiscal year.
The day-to-day scope includes Accounts Payable, Accounts Receivable, and Cost of Goods accounts. Periodic reporting covers insurance, taxes and duties, and valuing the business for purchase or sale. Unleashed notes that inventory accounting is the method of accounting dealing with the inventory assets of a business.
Inventory is an asset a business holds for sale in its normal operations or uses to produce goods for sale. The same item can be inventory or a fixed asset depending on the business model. A car dealership treats cars as inventory. A car rental company treats cars as long-term or non-current assets, according to QuickBooks.
What are the main types of inventory in accounting?
Merchandising businesses buy ready-made products and resell them. Supermarkets and clothing stores fall into this category. Their inventory is the finished product sitting on the shelf, ready to sell, according to QuickBooks.
Manufacturing businesses carry three layers of inventory. Raw materials are the inputs not yet used in production. Work-in-progress is partially completed product on the production floor. Finished goods are completed items ready for sale. A manufacturer reports all three layers on the balance sheet.
Service businesses usually carry no inventory. That is why their accounting looks different. A service firm has no stock to value, no cost of goods sold tied to physical product, and no inventory turnover metric to manage. The inventory conversation applies to businesses that buy, make, or hold physical goods.
How do you calculate beginning and ending inventory?
Beginning inventory equals the ending inventory of the previous accounting period. The number carries forward from one period to the next. Unleashed states the formula clearly: Beginning inventory equals Cost of Goods Sold plus Ending Inventory minus Net Purchases.
Ending inventory is calculated as Beginning Inventory plus Net Purchases minus Cost of Goods Sold. This formula is the closing balance that becomes the next period's opening balance. Getting either number wrong distorts cost of goods sold and gross margin for the period.
Inventory turnover measures the rate at which a company sells, uses, and replaces its inventory. It is a health metric for product businesses. Small improvements in inventory accuracy compound. According to Gitnux data cited by Unleashed, a 1% improvement in inventory accuracy reduces stock count errors by roughly 7%.
Which inventory costing method should you use — FIFO, LIFO, weighted average, or specific identification?
Specific identification suits high-value unique items like cars and jewelry. Each item carries its own cost, and the books track that cost individually. FIFO, or first-in, first-out, suits perishable goods like food and medicine. The oldest stock is assumed to sell first, which matches physical flow for perishable products.
LIFO, or last-in, first-out, is used for tax benefits but is prohibited in some countries. Weighted average cost suits large inventory volumes with mixed costs. The method blends all purchase costs into a single average cost per unit, according to QuickBooks.
The method choice changes cost of goods sold, gross margin, and taxable income. A business should apply the chosen method consistently once selected. The research sources do not detail current US GAAP or IFRS valuation rules such as lower of cost or market. Confirm the applicable standard for the current tax year with a qualified professional.
What is the difference between periodic and perpetual inventory systems?
Periodic inventory systems update inventory records at set intervals. A business counts stock at month-end or quarter-end and adjusts the books. Perpetual inventory systems update continuously with each purchase and sale. Every transaction flows through the inventory ledger in real time, according to QuickBooks.
The system choice affects how often the books reflect actual stock. Periodic systems leave the books stale between counts. Perpetual systems keep a running balance. The reconciliation work lands differently too. Periodic systems concentrate reconciliation at period end. Perpetual systems spread it across the period but require disciplined data entry.
When does inventory become yours — and how do shipping terms and consignment change the books?
Under FOB shipping point terms, the buyer takes ownership as soon as goods leave the seller's location. The buyer also covers transportation costs. Under FOB destination terms, the seller keeps ownership until the goods reach the buyer. The seller pays shipping, according to QuickBooks.
In consignment, the consignor remains the owner until the items are sold. The goods stay in the consignor's inventory records even though they sit in the consignee's location. The consignee does not own the stock and does not record it as inventory.
Getting these terms wrong puts stock on the wrong company's books. That distorts cost of goods sold at period end. A business that records FOB destination goods too early overstates inventory and understates cost of goods sold. The error flows into gross margin and taxable income.
How does multi-state sales tax connect to inventory accounting?
Nexus is a connection to a state that creates a sales tax obligation. Inventory held in a state, including inventory in a fulfillment or warehouse arrangement, is one of the facts that can create nexus. A product business with stock sitting in another state may owe sales tax there even without a physical office.
Clean inventory records are what make it possible to quantify exposure and get current with each state. That is the work Spencer Accounting Group does through Sales Tax Resolution, which covers nexus review, exposure quantification, voluntary disclosure, and getting current with each state. Spencer Accounting is 100% virtual and serves clients in any state or country, with no office visit required.
Key Takeaways
- Inventory accounting is the practice of valuing and reporting on the physical inventory a business holds, and inventory sits on the balance sheet as a current asset.
- Beginning inventory equals the prior period's ending inventory, and can be calculated as Cost of Goods Sold plus Ending Inventory minus Net Purchases.
- Ending inventory is calculated as Beginning Inventory plus Net Purchases minus Cost of Goods Sold.
- Manufacturing inventory has three layers: raw materials, work-in-progress, and finished goods, while merchandising inventory is the finished product itself.
- Under FOB shipping point the buyer owns the goods once they leave the seller; under FOB destination the seller owns them until delivery.
- In consignment, the consignor keeps ownership and the goods stay in the consignor's inventory records until sold.
- FIFO, LIFO, weighted average, and specific identification each fit different inventory profiles, and the method chosen changes cost of goods sold and taxable income.
References
- Inventory Accounting — Unleashed, published June 17, 2024, updated June 4, 2026
- Inventory Accounting: A Beginner's Guide — QuickBooks Global, published July 28, 2022, updated January 31, 2025
- Inventory Accounting — YouTube, published March 26, 2025