Bookkeeping for Amazon Sellers: The Complete Guide | VarStan
Learn how proper bookkeeping for Amazon sellers can save you thousands in taxes, keep you compliant, and help your business grow. Expert tips from VarStan.
If you're selling on Amazon, you already know the hustle: sourcing products, managing inventory, optimizing listings, and chasing the Buy Box. What often gets pushed to the back burner? Your books.
It's an easy trap to fall into. But neglecting bookkeeping as an Amazon seller isn't just inconvenient — it can quietly erode your profits, trigger IRS audits, and leave you flying blind when it's time to scale or sell your business.
Here's everything you need to know about bookkeeping for Amazon sellers, done right.
Why Bookkeeping for Amazon Sellers Is Different
Selling on Amazon isn't like running a traditional brick-and-mortar store. Your financials are more complex than most small businesses because you're dealing with:
Amazon fees — referral fees, FBA fulfillment fees, storage fees, advertising costs
Multi-state sales tax — Amazon's fulfillment network creates sales tax nexus in multiple states
Inventory tracking — COGS (cost of goods sold) must be accurately tracked to calculate real profit
International sales — currency conversion, VAT, and cross-border tax rules
Returns and refunds — these need to be properly recorded to avoid overstating revenue
Reimbursements — Amazon regularly issues reimbursements for lost or damaged inventory that must be accounted for
Miss any one of these, and your profit and loss statement is telling you a story that isn't quite true.
The #1 Mistake Amazon Sellers Make with Their Books
Treating their Amazon Seller Central deposits as income.
Here's the problem: the amount Amazon deposits into your bank account every two weeks is not your revenue. It's your revenue minus fees, minus refunds, minus Amazon's reserve — a net figure that tells you very little about how your business is actually performing.
Proper bookkeeping breaks that deposit down into its components: Gross product sales, Amazon referral fees, FBA fees, Advertising spend, Refunds issued, Reimbursements received.
Only when these are separated can you truly understand your margins and make smart pricing and sourcing decisions.
Cash Basis vs. Accrual Accounting: Which Should Amazon Sellers Use?
For most small Amazon sellers, cash basis accounting is simpler and perfectly acceptable for tax purposes. You record income when you receive it and expenses when you pay them.
However, as your business grows — especially if you're carrying significant inventory — accrual accounting gives you a much more accurate picture of your financial health. It matches revenue and expenses to the period they belong to, regardless of when cash changes hands.
If you're planning to seek financing, bring on investors, or eventually sell your Amazon business, accrual-basis financials are typically required.
Not sure which is right for you? A professional bookkeeper who specializes in Amazon can assess your situation and guide you to the right method.
Sales Tax: The Sleeping Giant for Amazon Sellers
Since the 2018 South Dakota v. Wayfair Supreme Court ruling, economic nexus laws have changed everything for online sellers. You may now owe sales tax in states where you have no physical presence — just significant sales.
For Amazon FBA sellers, it gets more complicated: Amazon stores your inventory in fulfillment centers across the country, potentially creating physical nexus in dozens of states without you even realizing it.
What you need to track: which states your inventory is warehoused in (Amazon's Inventory Ledger report helps here); whether you've crossed economic nexus thresholds in key states; whether you're registered to collect and remit sales tax in each required state.
Amazon does collect and remit sales tax on your behalf in most states through Marketplace Facilitator laws — but not all, and the rules change frequently. A bookkeeper who understands Amazon's tax landscape will make sure you're not caught off guard.
Inventory Tracking: Where Profits Go to Hide
Inventory is usually an Amazon seller's biggest asset and biggest expense. Yet it's also one of the most commonly mismanaged areas of bookkeeping.
Poor inventory tracking leads to overstating profits (and overpaying taxes), understating profits (and missing growth signals), cash flow surprises when stock runs out, and inaccurate COGS that distort your true margins.
The gold standard is tracking inventory using the FIFO (First In, First Out) method, which matches the earliest purchased inventory against sales first. This is both IRS-compliant and generally the most accurate reflection of your actual cost structure.
Good bookkeeping software paired with Amazon's inventory reports can automate much of this tracking — but it needs to be set up correctly from the start.
Tools Amazon Sellers Should Use
Here are the most commonly used tools for Amazon seller bookkeeping: QuickBooks Online (industry standard, integrates well with Amazon data); Xero (a popular QuickBooks alternative, especially for international sellers); A2X (a dedicated Amazon-to-accounting integration that automatically categorizes your settlements); Gusto or ADP (if you have employees or contractors); Expensify or Bill.com (for expense tracking and vendor payments).
The tools themselves are only as good as the bookkeeper using them. Software doesn't know whether a reimbursement should be categorized as income or an inventory credit — that's where human expertise matters.
When to Hire a Professional Amazon Bookkeeper
Many sellers start with DIY bookkeeping on a spreadsheet. That works — for a while. Here are the signs it's time to bring in a professional: you're spending more than 3–4 hours per month on your books; you're not confident your COGS are accurate; tax season catches you by surprise every year; you've received a notice from the IRS or a state tax authority; you're planning to scale, take on a partner, or sell your business; you're selling internationally or across multiple Amazon marketplaces.
A specialist Amazon bookkeeper pays for themselves quickly — in tax savings, avoided penalties, and the time you get back to focus on growing your store.
What to Look for in an Amazon Bookkeeping Service
Not all bookkeepers understand the Amazon ecosystem. When evaluating a service, ask: Do you specialize in Amazon FBA/FBM sellers? How do you handle Amazon settlement reconciliation? Can you help with multi-state sales tax compliance? What accounting software do you use, and will I have access? How do you communicate with clients — and how quickly do you respond? Are you cloud-based, and can you work with my existing setup?
A great Amazon bookkeeping partner doesn't just record transactions — they help you understand your numbers and make smarter business decisions.
The Bottom Line
Running an Amazon business without proper bookkeeping is like navigating with a broken compass. You might be moving fast, but you don't know if you're heading in the right direction.
With accurate, Amazon-specific bookkeeping in place, you'll know your true profit margins, stay compliant with sales tax obligations, be prepared for tax season year-round, and have the financial clarity to confidently grow your business.
VarStan specializes in bookkeeping for Amazon sellers. Our team has supported thousands of Amazon businesses across more than 200 industries, and we handle everything remotely — so you can focus on selling while we handle the numbers.