The Amazon low-inventory-level fee hits standard-size items when your days of supply runs too thin. How the 28-day threshold works and how to avoid it.
It is an extra per-unit fee on standard-size FBA products when your historical days of supply stays below Amazon's threshold, which has run around 28 days. Amazon applies it because running thin and replenishing constantly is less efficient for its fulfillment network. Keeping enough cover avoids it entirely.
How do I avoid the low-inventory-level fee?
Maintain enough days of supply on your standard-size SKUs to stay above Amazon's threshold (around 28 days of historical supply). That means reordering on time so cover does not chronically run thin. It is the mirror image of avoiding aged-inventory surcharges: hold the right amount, not too little and not too much.
Andrew Erickson is the founder of Inventory Hero. He has spent years working with Amazon FBA sellers on demand forecasting, restock planning, and the cash flow side of running a private-label brand. Inventory Hero exists because every spreadsheet-based inventory system he tried eventually broke — usually right before Q4.
Does the low-inventory-level fee apply to all products?
It applies to standard-size items, both small and large standard. Oversize products and some categories have been scoped differently, so the fee mainly bites the standard-size SKUs that are replenished frequently. Your monthly storage-and-fees report in Seller Central shows which of your SKUs were actually charged.
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The Amazon low-inventory-level fee is an extra per-unit charge on standard-size FBA items when your historical days of supply runs too thin, with the threshold sitting around 28 days of supply. The short version: Amazon penalizes chronically low cover because constantly replenishing thin inventory is inefficient for its network, and you avoid the fee by simply holding enough stock. Below is how the fee works, why Amazon charges it, and how to stay above the line.
The low-inventory-level fee is a per-unit charge Amazon adds to standard-size products when their historical days of supply stays below a threshold, which has run around 28 days.1 It is based on your trailing sales and inventory, so it is triggered by a pattern of thin cover, not a single low day. See the low-inventory-level fee definition for the short form.
The logic from Amazon's side is operational. When a SKU is constantly running low and being topped up in small, frequent shipments, it is more expensive for Amazon to receive, store, and fulfill than a SKU held at a healthy level. The fee passes that inefficiency back to the seller.
The charge is per unit and scales with how far below the threshold your cover sits, so there is no single flat number that applies to every SKU. To see whether you are actually being charged and how much, check the FBA fee preview in Manage Inventory for a SKU, or your monthly storage-and-fees report in Seller Central, which itemizes it. If you just got hit with it, that report is where the exact amount lives.
The threshold itself is easy to check, because days of supply is just your stock divided by your daily sales. A SKU selling 8 units a day with 160 units in FBA has 160 / 8 = 20 days of supply, which is below the 28-day line and the kind of thin cover that can trigger the fee. The same SKU held at 300 units has about 37 days of supply, comfortably clear of it. The question is always how your historical cover compares to that roughly 28-day floor.
It is easy to see the low-inventory-level fee and the aged-inventory surcharge as contradictory, one for too little stock and one for too much. They are really two ends of the same message: Amazon wants you holding the right amount of inventory. Too little and you get the low-inventory fee; too much and you get storage plus aging surcharges. The healthy middle, enough cover to stay in stock without sitting on a pile, is exactly what good restock planning produces.
This is why the fee is not really a fee problem; it is an inventory-planning problem. A SKU that chronically trips the low-inventory fee is usually one you are under-ordering or reordering late.
Avoiding the fee comes down to maintaining enough cover on your standard-size SKUs:
Hold above the threshold. Keep your historical days of supply comfortably above the roughly 28-day line on standard-size items. That means treating 28 days as a floor to stay above, not a target to hit.
Reorder on time. Chronically thin cover is usually a timing problem. Set a reorder point that accounts for your full lead time and fire it on schedule, so stock arrives before cover runs down. Size it in the reorder point calculator.
Buffer the spiky SKUs. Products with variable demand dip below the line more easily, so they need a bit more cover and safety stock to stay above it.
Watch the trailing window. Because the fee is based on historical days of supply, a stretch of thin cover can keep affecting you even after you restock. Avoid letting it get thin in the first place.
The one caution: do not over-correct into the opposite problem. Flooding a SKU with inventory to clear the low-inventory fee can push you into storage and aging surcharges. The answer is the right cover, sized per SKU, not the most.
The Amazon low-inventory-level fee is a per-unit charge on standard-size items whose historical days of supply runs too thin, around a 28-day threshold, charged because constantly replenishing thin stock is inefficient for Amazon. You avoid it by holding enough cover and reordering on time, the same per-SKU discipline that keeps you clear of aging surcharges at the other extreme. For the full fee picture, see Amazon FBA fees 2026.