Accounting & Tax for Amazon FBA Sellers

CPA Services for Amazon FBA Sellers

Amazon FBA sellers face tax complexity that rivals businesses ten times their size. The moment you ship inventory to Amazon, their algorithm redistributes your products across 175+ fulfillment centers nationwide. You now have physical nexus in dozens of states you have never visited, creating sales tax registration obligations, potential income tax filing requirements, and compliance exposure that most CPAs have never dealt with. I work with FBA sellers every day, and I know exactly how to untangle the mess.

The single most expensive bookkeeping mistake FBA sellers make is recording net Amazon deposits as revenue. Amazon reports gross sales on your 1099-K, which includes the item price, shipping charges, and sales tax collected. It does not subtract referral fees (typically 15% of sale price), FBA fulfillment fees, storage fees, return processing fees, or the sales tax Amazon remitted on your behalf. A seller with $250,000 in gross sales might only see $165,000 in net bank deposits, but the IRS receives a 1099-K showing $250,000. If you report $165,000 on Schedule C Line 1, you will receive a CP2000 notice 12 to 18 months later showing $85,000 in unreported income. The fix is straightforward but requires proper accounting: report gross revenue on Line 1 to match the 1099-K, then deduct every Amazon fee on the appropriate expense lines. I set up this reconciliation system for every seller client from day one.

Cost of Goods Sold is typically the largest expense line for any physical product business, and most sellers calculate it wrong. True COGS for an FBA seller is not just the unit price you paid your manufacturer. It is the full landed cost: product cost plus ocean freight, customs duties and tariffs (Section 301 rates of 7.5% to 25% on Chinese goods, plus the temporary 15% global tariff under Section 122), customs brokerage fees, cargo insurance, domestic drayage from port to Amazon, inbound placement fees, and prep and labeling costs. On $100,000 in product purchases from China, freight and duties typically add $15,000 to $25,000 in additional costs. Missing those COGS components means overstating your net income and overpaying taxes by $3,750 to $9,250 at a 25% effective rate.

Amazon settlement reports are generated every two weeks and are only retained in Seller Central for 90 days. If you do not download and archive them, you lose the detailed transaction data permanently. Each settlement contains gross product sales, shipping credits, promotional rebates, refunds, referral fees, FBA fulfillment fees, storage fees, subscription fees ($39.99/month for Professional accounts), reimbursements for lost or damaged inventory, and other adjustments. The correct bookkeeping approach uses a clearing account model: post each settlement as a categorized journal entry to an Amazon Clearing account, then match the ACH deposit when it hits the bank. Integration tools like A2X ($29 to $229/month depending on volume) or Link My Books ($21 to $249/month) automate this breakdown and post properly categorized entries to QuickBooks Online that match your bank deposit to the penny.

All 45 states with a sales tax plus Washington D.C. have enacted marketplace facilitator laws, which means Amazon calculates, collects, and remits sales tax on marketplace transactions. Many sellers assume this means they are done with sales tax. They are wrong. Marketplace facilitator laws only cover sales made through the marketplace. If you also sell through Shopify, your own website, wholesale channels, or trade shows, you must independently register, collect, and remit sales tax in every state where you have nexus. Even marketplace-only sellers are required to register and file zero-dollar returns in states like Washington, Pennsylvania, and Connecticut once nexus is triggered. Failure to file even a zero-dollar return while holding an active permit triggers penalties in virtually every state. The dominant economic nexus threshold is $100,000 in sales, with California, New York, and Texas set higher at $500,000. NJ uses $100,000 OR 200 transactions.

Multi-state income tax is the compliance burden most sellers overlook entirely. Owning inventory stored in a state creates income tax nexus because it exceeds the protections of Public Law 86-272. California is the most aggressive enforcer. In Diet Standards LLC v. FTB (California Office of Tax Appeals, October 2025), the OTA ruled that having any inventory in California FBA warehouses constitutes 'doing business' under R&TC Section 23101(a), regardless of how small the inventory value or sales amount. The OTA explicitly rejected the argument that California's bright-line factor presence thresholds ($75,707 in property, $757,070 in sales) function as a safe harbor. Every FBA seller using Amazon's fulfillment network almost certainly has inventory in California, triggering an $800 annual minimum franchise tax plus potential penalties for each unfiled year. I help sellers evaluate their multi-state income tax exposure and prioritize compliance in the highest-risk states: California, New York, and any state with significant sales volume.

S-Corp election is one of the biggest tax-saving opportunities for profitable Amazon sellers. As a sole proprietor, all net income is subject to 15.3% self-employment tax (12.4% Social Security plus 2.9% Medicare) on 92.35% of net earnings. At $100,000 net profit, that is approximately $14,130 in SE tax. With an S-Corp election and a $45,000 reasonable salary, payroll tax drops to roughly $6,885, saving approximately $7,245 per year. At $200,000 net profit with a $70,000 salary, annual savings reach $13,000 to $20,000. The S-Corp election generally makes financial sense once net profit consistently exceeds $60,000 to $80,000, after accounting for the additional compliance costs: payroll processing ($500 to $2,400/year), Form 1120-S preparation ($1,000 to $3,000), and the NJ minimum Corporation Business Tax ($375 to $1,500 based on gross receipts). NJ automatically recognizes the federal S-Corp election since December 22, 2022 (P.L. 2022, c. 133), so no separate state filing is required.

Reasonable compensation for seasonal FBA businesses presents a unique challenge. The IRS evaluates what it would cost to hire someone to perform the owner's duties: supply chain sourcing, listing optimization, PPC management, inventory planning, and financial oversight. An e-commerce operations manager salary of $35,000 to $65,000 provides a defensible benchmark. For a seller netting $100,000 with revenue concentrated in Q4, a salary of $35,000 to $50,000 is typically defensible. If cash flow is tight during a capital-intensive product launch, you can temporarily forego compensation, but you must catch up in a later quarter. An arbitrary 50/50 salary-to-distribution split without supporting analysis is a known IRS audit trigger per Watson v. Commissioner (668 F.3d 1008, 8th Cir. 2012).

Inventory valuation method matters and must be applied consistently. FIFO (First-In, First-Out) is the most commonly recommended method because it aligns with how Amazon typically fulfills orders and provides accurate balance sheet valuation with ending inventory at newer costs. Weighted average cost is a practical alternative when price differences between batches are small. Once adopted, changing methods requires IRS approval via Form 3115. Under the lower-of-cost-or-market method, slow-moving or obsolete FBA inventory can be written down. Amazon reimbursements for lost or damaged inventory should be recorded as Other Income, not sales revenue. As of March 31, 2025, Amazon reimburses based on manufacturing cost rather than selling price, significantly reducing recovery amounts. Claim windows are tight: 60 days for fulfillment center issues, 60 to 120 days for return discrepancies.

The OBBBA (One Big Beautiful Bill Act, signed July 4, 2025) introduced several changes directly affecting FBA sellers. The 1099-K threshold was permanently restored to $20,000 in gross payments AND 200+ transactions, killing the planned $600 threshold. Section 174A permanently reinstates full expensing for domestic R&E expenditures, but foreign R&E (such as paying Chinese manufacturers for mold development or product engineering) must still be amortized over 15 years. Small businesses under $31 million in receipts can retroactively elect expensing for 2022 to 2024 by amending returns before July 4, 2026. The 1099-NEC threshold increased from $600 to $2,000 for payments made after December 31, 2025. Section 321 de minimis ($800 duty-free threshold) was eliminated for Chinese goods in May 2025, suspended globally in August 2025, and permanently repealed effective July 1, 2027. 100% bonus depreciation is now permanent for qualifying property acquired after January 19, 2025.

NJ-based FBA sellers benefit from the state's single sales factor with market-based sourcing for income apportionment. Sales of tangible goods are sourced to where the buyer receives the product. If a seller generates $500,000 in total sales with only $50,000 delivered to NJ customers, just 10% of income is apportioned to NJ for Corporation Business Tax purposes. This is highly favorable compared to the old three-factor formula. The NJ Pass-Through Entity Tax (BAIT) allows S-Corps to pay NJ income tax at the entity level, creating a federal deduction that effectively circumvents the $40,000 SALT cap (OBBBA, 2025-2029). BAIT rates range from 5.675% on the first $250,000 to 10.9% on income over $1,000,000. Single-member LLCs and sole proprietors are not eligible for BAIT, which is another driver toward the S-Corp election. NJ LLC formation costs $125 plus $75/year for the annual report, and forming in Delaware or Wyoming provides zero tax advantages for a NJ-based seller.

Voluntary Disclosure Agreements offer a lifeline for sellers who have been selling for years without registering in nexus states. Most states waive 100% of penalties and limit the look-back period to 3 to 4 years under a VDA, compared to unlimited exposure if the state initiates the audit first. VDAs can be initiated anonymously through a representative. The Multistate Tax Commission offers consolidated multi-state applications for sellers needing to disclose in multiple states simultaneously. If you have been selling through FBA for more than a year without registering in states where Amazon stores your inventory, the exposure is real and growing. States are actively purchasing marketplace data and forming multi-state task forces to identify non-compliant sellers.

Every Amazon FBA seller client works directly with me. I'm Greg Monaco, CPA. No junior staff. No handoffs. Whether you are doing $100K in revenue or $2 million, I will clean up your books, reconcile your 1099-K, set up proper COGS tracking, evaluate your entity structure, and make sure you are not leaving money on the table or exposing yourself to state audit risk.