eCommerce Accounting: How to Handle Sales Tax, COGS, Refunds & Multi-Channel Revenue

eCommerce accounting is fundamentally more complex than traditional retail. You sell across multiple channels, process payments through various gateways, ship to dozens of tax jurisdictions, and handle returns at scale.

Key Takeaways

• Record gross revenue and fees separately — never book only the net payout amount, as this understates both revenue and costs.
• FIFO is the recommended inventory valuation method for most eCommerce businesses because it matches physical goods flow.
• Economic nexus (post-Wayfair) means selling above $100K or 200 transactions in a state creates tax obligations without physical presence.
• eCommerce return rates average 20-30% — maintain a returns reserve and reconcile refunds per channel monthly.
• Reconcile payment gateway deposits weekly and full bank reconciliation monthly to catch discrepancies early.

Revenue Recognition for Multi-Channel Sellers

Record revenue at the point of sale (accrual basis), not when the payout arrives. Record gross revenue and fees separately. Reconcile marketplace payouts to individual orders. Use separate revenue accounts per channel for profitability analysis.

Cost of Goods Sold (COGS)

eCommerce COGS includes product cost, inbound shipping, customs duties, packaging materials, direct picking/packing labor, and FBA fulfillment fees. COGS does not include marketing, overhead, software, or hosting.

FIFO (First In, First Out) is recommended for most eCommerce businesses because it matches the physical flow of goods and provides accurate balance sheet valuation. Odoo's inventory module calculates COGS automatically using your chosen valuation method.

Sales Tax and Nexus

After the 2018 Wayfair decision, states can require tax collection from businesses with no physical presence. Nexus is created by physical presence, economic threshold ($100K/200 transactions), marketplace facilitator laws, or click-through affiliates.

In most US states, marketplace facilitators (Amazon, Shopify, eBay) collect and remit tax on your behalf. Sales through your own website still require you to collect and remit in nexus states.

Refund and Return Accounting

Issue a credit memo reversing the original sale. Reverse COGS if the product is restocked; write off COGS if damaged. Record return shipping as a separate expense. Process refunds on the date issued, not the date the return is received. Maintain a returns reserve based on historical rates.

Payment Gateway Reconciliation

Download settlement reports from each gateway (Stripe, PayPal, Square). Match gross amounts to individual orders. Verify fee deductions. Account for holds and reserves as receivables. Reconcile the net deposit to your bank statement.

Frequently Asked Questions

Q: Should eCommerce businesses use cash or accrual accounting? A: Accrual accounting is strongly recommended. Cash basis does not properly account for inventory as an asset, does not recognize revenue until marketplace payouts arrive weeks after the sale, and does not match COGS to the period products are sold.

Q: How do I account for Amazon FBA fees? A: Separate them into categories: referral fees (selling expense), FBA fulfillment fees (COGS or shipping), storage fees (warehouse expense), and advertising fees (marketing). Do not lump all fees into a single category.

Q: What is the best accounting software for eCommerce? A: For businesses under $1M revenue, QuickBooks Online or Xero with integrations works well. For growing businesses with inventory complexity and multi-channel operations, Odoo provides the most comprehensive solution. See our software comparison.

Q: How often should I reconcile my eCommerce accounts? A: Payment gateway deposits weekly, full bank reconciliation monthly. For high-volume sellers (1,000+ orders/month), weekly full reconciliation is recommended.

Next Steps

ECOSIRE provides accounting services tailored to eCommerce including multi-channel reconciliation, COGS tracking, and tax compliance across Odoo, QuickBooks, and Xero. Contact our team for a free assessment.