Amazon FBA Accounting: Reserves, Fees, and Sales Tax

Amazon Fulfilled By Amazon (FBA) sellers hit a scale of operational complexity that catches most retailers by surprise. Inventory sits in Amazon warehouses in six or ten different states. Sales tax gets collected by Amazon in most jurisdictions but by the seller in others. Fees stack in three or four categories. Cash lands in the bank every two weeks with none of the underlying detail visible without a settlement report reconciliation.

For a Boise-based FBA brand doing $3 million a year or a Utah manufacturer selling direct through FBA on top of B2B channels, getting the bookkeeping right is a real project, not a bookkeeper’s afterthought.

The Chart of Accounts an FBA Seller Actually Needs

A working FBA chart of accounts separates each economic event that Amazon combines into settlement deposits. At minimum:

• 4000 Gross Product Sales
• 4010 Refunds and Returns (contra-revenue)
• 5000 Cost of Goods Sold (landed cost of units sold)
• 5100 Amazon Referral Fees
• 5200 FBA Fulfillment Fees (pick, pack, ship)
• 5300 Storage Fees (monthly + peak-season surcharges)
• 5310 Long-Term Storage Fees (aged inventory penalty)
• 5320 Removal, Disposal, and Return-Processing Fees
• 5400 Chargebacks and A-to-Z Guarantee Claims
• 6100 Amazon Advertising (PPC and DSP)
• 1200 Amazon Reserve Balance (asset)
• 2100 Sales Tax Collected (liability)

The revenue and COGS split matters because it produces a clean gross margin figure that ties back to unit-level profitability analysis.

Reserves: What They Are and How to Book Them

Amazon holds a portion of every seller’s earnings in a reserve balance. Reserves cover potential refunds, chargebacks, and A-to-Z claims, and they can shift up or down each settlement period. From a bookkeeping standpoint, reserves are money Amazon owes the seller, not lost revenue.

The correct treatment records gross sales as revenue when the transaction occurs, books fees to their respective expense accounts, and reports the reserve balance as a receivable (Amazon Reserve, current asset). When the reserve releases, it moves from receivable to cash. This preserves accurate revenue and margin figures regardless of how much cash Amazon is holding on any given day.

Fee Categorization: Referral, FBA, Storage, Long-Term

Referral fees are Amazon’s marketplace commission, typically 8 to 15 percent depending on category. They tie directly to each unit sold and belong in cost of goods sold.

FBA fulfillment fees cover pick, pack, and ship, priced per unit and by size/weight tier. They also tie to units sold and belong in COGS or a fulfillment expense line.

Storage fees are monthly per cubic foot, with peak-season surcharges typically running October through December. Storage costs correlate with inventory levels, not units sold, so many sellers book them to a separate fulfillment expense line rather than COGS. That treatment makes aged inventory visible as an expense drag.

Long-term storage fees kick in for inventory aged past defined thresholds (typically 180 to 365 days). These are a red flag category. Any long-term storage fee larger than a few percent of storage cost signals inventory that should be liquidated, disposed of, or removed.

Marketplace Facilitator Sales Tax: When You Owe What

Under marketplace facilitator laws, Amazon collects and remits sales tax on the seller’s behalf in most U.S. states. Sales tax collected by Amazon should not appear as seller revenue. Book it to a sales tax liability account and reverse when Amazon remits.

Complications: some states still require the seller to file a sales tax return showing marketplace sales even though Amazon remits the tax. Idaho and Utah generally require this informational filing. The bookkeeping needs to support it.

Inventory Valuation Across FBA Warehouses

FBA sellers have inventory sitting in multiple Amazon fulfillment centers simultaneously. From a GAAP standpoint, all of it is the seller’s inventory and belongs on the balance sheet. From a sales tax standpoint, inventory in a state can create nexus even if the seller never chose to store there.

The right treatment carries FBA inventory on the balance sheet at landed cost (product cost plus inbound freight, customs, and duty), pulls the inventory report from Amazon’s Inventory Ledger monthly, and reconciles the reported quantity to internal purchase and sales records.

Monthly Close Checklist for a Six- or Seven-Figure Seller

A monthly close for a scaled FBA seller includes:

• Reconcile Amazon settlement deposits to gross sales, fees, refunds, and reserve changes
• Update Amazon Reserve balance receivable from the current unavailable balance
• Reconcile Amazon Inventory Ledger to internal cost of goods sold
• Review long-term storage fees and flag aging inventory
• Verify marketplace-facilitated sales tax reversals for the period
• Review Amazon Advertising spend and reconcile to the advertising invoice
• Confirm chargebacks and A-to-Z claims are booked to the correct account

A well-set-up FBA close runs in a few hours per month. A neglected one can take days at year-end and produce a P&L that does not reflect the underlying business.

FBA accounting is not conceptually hard, but it has enough moving parts that most retailers benefit from working with a CPA who has seen the platform before. The retail advisory team at Cooper Norman sets up FBA and multi-marketplace charts of accounts for Idaho and Utah sellers and can automate the monthly reconciliation through tools like A2X or Link My Books. Our client accounting services group handles the monthly close for growing FBA operations.