Overview

Amazon provides sellers with an Aged Inventory Surcharge Report that breaks down exactly how much they're being charged for storing products in fulfillment centers beyond 180 days. This report is essential for FBA sellers looking to understand and manage their long-term storage costs, as it itemizes charges at the SKU level with full transparency into how each fee is calculated.

Key Points / What Sellers Need to Know

• Charges apply after 180 days — Any inventory sitting in Amazon's fulfillment centers for more than 180 days is subject to the aged inventory surcharge, making regular inventory turnover critical to profitability.
• Fees are volume-based — The surcharge is calculated using the cubic footage of each unit, not weight or item count, so bulky products face disproportionately higher charges.
• Age tiers determine rates — Amazon uses tiered pricing based on how long inventory has been stored (e.g., 181–210 days, 211–240 days, 241–270 days, etc.), with rates increasing the longer items remain in storage.
• SKU-level granularity — The report breaks down charges by individual SKU, allowing sellers to pinpoint exactly which products are driving their storage costs.
• Simple calculation formula — Each line item follows a straightforward formula: the per-unit surcharge rate (based on volume and age tier) multiplied by the number of charged units equals the total amount charged.

How the Surcharge Is Calculated

The aged inventory surcharge uses a transparent, formula-driven approach. For each SKU that has been in fulfillment centers beyond the 180-day threshold, Amazon calculates the per-unit rate by multiplying the item's volume in cubic feet by the applicable surcharge rate for its age tier. That per-unit rate is then multiplied by the number of units charged to produce the total amount. For example, if a product has a per-unit volume of 0.045 cubic feet and falls in the 241–270 day age tier with a rate that produces a per-unit surcharge of $0.07, two units would result in a charge calculated accordingly. To find your total aged inventory surcharge across all products, simply download the report and sum the values in the amount-charged column.