Amazon Low-Inventory Fee: How to Balance IPI and Margins

Inventory planning needs to balance stockout risk, storage cost, and low-inventory charges. Replenishing solely to improve an IPI score or avoid one fee can tie up more capital than the fee is worth.

Use Current Assessment Rules

Amazon’s 2026 US fee changes move low-inventory-level fee assessment from parent ASIN to FNSKU. Its help page explains historical days of supply using trailing demand and inventory averages. Historical supply is not the same as today’s sellable units divided by today’s sales.

Read the current product eligibility, exemptions, and fee tier in your account. Do not assume that a new child, low volume, or an AWD shipment automatically makes a particular unit exempt.

Separate Three Different Measures

• Forward cover: how much forecast demand current and incoming stock can meet.
• Historical days of supply: Amazon’s retrospective fee metric.
• IPI: an inventory performance indicator, not a direct calculation of this fee.

Make the Economic Decision

Estimate the extra storage, freight, and cash required for additional inventory, then compare that with expected fees and the cost of a stockout. Account for production and receiving variability. Seller Scale recommends setting the replenishment point from forecast demand over lead time plus an explicit safety buffer, not a universal 30–45-day target.

For a product being discontinued, adding a large batch just to avoid a low-stock fee can create a more expensive aging problem. Model the remaining contribution profit under both options.

Verify Waivers and Monitor Results

AWD-related waivers have qualifying conditions. Check whether the SKU meets the current auto-replenishment requirements rather than counting all AWD-stored goods as exempt. Review actual fee charges by FNSKU after the next cycle and investigate discrepancies with the relevant reports.

Sources and Scope

The linked sources support the documented points above. Recommendations and hypothetical calculations are editorial guidance, not Amazon rules or promised results. Check the current requirements for your marketplace and account before acting.

• Amazon low-inventory-level fee
• Amazon 2026 US fee changes
• Amazon AWD pricing