COGS vs Operating Expenses: How eCommerce Stores Should Classify Costs

COGS is the abbreviation for Cost of Goods Sold. Distinguishing COGS from operating expenses is essential for accurate gross margin calculation, tax reporting, and meaningful profit analysis in an eCommerce business.

The core distinction: COGS represents costs directly tied to producing or acquiring the goods sold, while operating expenses are the ongoing costs to run the business that do not directly create the product. Misclassification can inflate or understate gross margin and mislead management decisions about pricing, marketing spend, and SKU profitability.

Common Items Classified As COGS

For eCommerce sellers, common COGS items include:

• Purchased Inventory: Net supplier invoice costs for resale items.
• Landed Cost: Inbound freight, customs duties, and non-recoverable taxes that bring inventory to a sellable state.
• Direct Production Costs: Raw materials and direct labor allocated to goods manufactured for sale.

Common Operating Expenses (Not COGS)

Typical operating expenses include:

• Fulfillment And Customer Shipping: Outbound shipping to customers and third-party fulfillment fees (fulfillment can sometimes be partly capitalized; follow accounting policy).
• Sales And Marketing: Ad spend, influencer fees, and promotions.
• Administrative Costs: Office rent, software subscriptions, and payroll for non-production staff.

Gray Areas And Practical Rules

Some costs sit between the categories and require judgment. Use this practical guidance:

• Label: Ask whether the cost is necessary to get the item into sellable condition — if yes, capitalize it to inventory; if no, expense it as operating cost.
• Label: Allocate multi-purpose labor or facility costs only if there is a reasonable and documented basis to apportion them to production.
• Label: Document how fulfillment fees are treated — many merchants expense third-party fulfillment per-shipment instead of capitalizing per-unit handling unless fees vary with inventory storage.

How Misclassification Affects KPIs

Misclassifying a large recurring cost as COGS increases COGS and reduces gross margin, potentially hiding true contribution margins of SKUs. Conversely, treating costs that should be in COGS as operating expenses inflates gross margin and may lead managers to underprice products or over-invest in low-margin SKUs. Accurate classification ensures metrics like gross margin, contribution margin, and CAC payback are meaningful.

Examples And Scenarios

Scenario 1 — Inbound Packaging: Custom branded boxes purchased and used as part of delivering sellable condition are typically capitalized into inventory and included in COGS when sold.

Scenario 2 — Outbound Inserts: Marketing inserts placed in orders to encourage repeat purchases are usually expensed as marketing rather than included in COGS.

Controls And Accounting Best Practices

• Label: Maintain a written inventory capitalization policy covering which costs are added to inventory and which are expensed immediately.
• Label: Tie WMS and ERP item-level landed costs to SKU records so accounting entries flow cleanly into inventory accounts.
• Label: Review cost classifications quarterly with finance and operations to capture process changes (new fulfillment providers, kitting, or returns handling).

Tax And Audit Considerations

Tax authorities examine whether inventory costs are reasonable and consistently applied. For U.S. tax reporting, improper classification can lead to adjustments and penalties. External auditors test classification as part of revenue and inventory audit procedures, focusing on whether costs are supported and whether policies are applied consistently across periods.

In short, the COGS line should contain costs directly tied to making goods sale-ready; operating expenses should include the costs to sell and run the business. Clear policies, accurate landed-cost tracking, and regular reconciliations prevent misclassification and keep margin reporting reliable.