Fractional CFO Services for Amazon Sellers: What They Do and When You Need One
A fractional CFO helps an Amazon seller see which products really make money after fees, ads and returns, and plan the cash that inventory ties up for months. An accountant records what happened. A fractional CFO tells you what to reorder, what to cut and how much cash you will have in 13 weeks.

This matters most when your sales are growing but your bank balance is not.
Why Amazon finances are hard to read
Amazon does not give you a profit and loss statement. It gives you sales, and a long list of fees, refunds and payouts that you have to turn into one. According to Novadata's Amazon accounting guide, the main problems are:
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Many fee types. Referral fees, FBA fulfillment fees, storage fees, aged-inventory surcharges, removal fees and returns processing fees are charged separately. Storage fees are higher from October to December.
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Refunds cost more than the sale. Refunds reduce gross sales, and Amazon can keep part of the referral fee on a refund.
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Cash is stuck in stock. The guide says cash can be tied up in inventory for 60 to 120 days, from order to payout.
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Data does not fit your accounting tool. Amazon data can't simply be loaded into QuickBooks or Xero.
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Taxes depend on where you sell. Amazon collects sales tax in most US states, but you may still owe home-state obligations, and selling abroad triggers VAT.
The result: revenue looks healthy while the real margin per product, and the cash left after the next purchase order, stay unclear.
What a fractional CFO does for an Amazon seller
A fractional CFO is a senior finance leader who works with you part-time. For an Amazon seller the work usually covers:
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A real P&L. Fees, ads, refunds and COGS (including shipping to Amazon, duties and prep) brought into one monthly report.
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Profit per product. Contribution margin by SKU and by channel after ads, fees and returns, so you can see which listings to scale and which to drop.
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Inventory and cash planning. Reorder timing and quantities, tied to lead times and to the cash that stock will absorb. A rolling 13-week cash forecast is the standard tool.
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Ad spend discipline. Whether advertising pays back, using measures like ACoS, TACoS and payback period.
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Financing. Inventory loans, credit lines and investor materials, with a view on what each costs.
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Multichannel view. Amazon next to Shopify, wholesale or other marketplaces, so the whole business is compared on one basis.
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Working with your accountant. The CFO sets up what reports are needed. The accountant keeps the books and files taxes.
Six numbers to track every month
If your CFO reports these six, you will see problems early.
| Metric | How it is calculated | Why it matters |
|---|---|---|
| Contribution margin per SKU | Revenue minus COGS, Amazon fees, ads and returns, for one product | Shows which listings actually earn money |
| ACoS | Ad spend divided by ad-attributed sales | Tells you if a campaign pays for itself |
| TACoS | Total ad spend divided by total sales | Shows if ads build organic sales over time |
| Days of inventory | Stock on hand divided by average daily units sold | Warns of stockouts and of overstock that triggers storage fees |
| Cash conversion cycle | Days from paying the supplier to receiving the Amazon payout | Sets how much cash you need to grow |
| 13-week cash balance | Forecast of receipts and payments by week | Shows the weeks when a purchase order will leave you short |
Contribution margin is the one most sellers don't have. Revenue and ad reports are easy to pull. A margin that includes every fee and return takes work to build.
When it is time, what it costs, and what to ask
Signs you need one:
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Sales are growing but cash is not, and you can't explain why.
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You can't say which ASINs are profitable after all fees and ads.
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Each purchase order is a gamble on whether you can pay for the next one.
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You are on cash-basis books and your inventory is large. Novadata suggests moving to accrual accounting once inventory passes $50K or revenue passes $500K.
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You are planning a loan, an investor round or a sale.
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You also sell on Shopify, wholesale or abroad, and the numbers don't line up.
What it costs. Prices vary by firm and scope. For reference, EcomBalance says most ecommerce brands pay $3K to $10K per month. John Galt Finance lists Essential Finance from €1,800 per month, with higher tiers quoted individually. For comparison, our pricing table shows an in-house CFO at €70K to €120K per year.
Questions to ask before hiring:
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Which Amazon sellers of my size do you work with?
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How do you calculate profit per SKU, including FBA and storage fees and returns?
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Can you show a sample 13-week cash forecast?
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How do you handle accrual accounting and reconciling Amazon payouts?
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Who joins my monthly call, and how senior are they?
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How do you work with my accountant, and what tools do you use?
An example: an Amazon and Shopify brand under cash pressure
Remilia Hair, a hair care brand selling on Amazon and Shopify and to retailers, faced a severe liquidity crisis. Short-term, high-interest loans drained monthly cash, and production lead times of 120 to 150 days tied up capital.
We built a real-time financial dashboard and a 12-month cash runway tracker to prioritize payments to vendors and lenders. We also planned inventory orders around 150-day lead times and compared the unit economics of Amazon influencer campaigns with Shopify growth. The case page reports that the debt was restructured, high-interest loans were retired, cash flow stabilized and Amazon sales grew. It does not publish figures for these results.
Talk to us
If you sell on Amazon and your numbers don't answer "which products pay, and what will my cash be after the next order?", John Galt Finance can help. Book a free call and we will tell you plainly whether a fractional CFO makes sense at your stage.
Sources
Pages opened on 2026-10-14.
Photo: Kelly Sikkema on Unsplash.
















