What is the aged inventory surcharge?
The aged inventory surcharge is the penalty fee Amazon applies to FBA units that have been sitting in fulfillment centers for more than 180 days. It replaced what Amazon previously called the “long-term storage fee” and starts hitting much earlier than it used to. The surcharge is charged monthly, on top of regular monthly storage fees, based on the cubic footage of each unit.
What makes this surcharge dangerous is the escalation. The jump from the 181-day tier ($0.50 per cubic foot) to the 271-day tier ($5.45 per cubic foot) is a 990% increase triggered by a single day of aging. Inventory that cost you $0.08 per unit in surcharges at day 270 suddenly costs $0.82 per unit at day 271. That cliff catches sellers who are not tracking inventory age at the SKU level.
Amazon assesses the surcharge continuously based on inventory age, not on a monthly snapshot. Every unit has its own age clock starting from the date it arrives at the fulfillment center. Units from different shipments of the same ASIN can be in different age tiers simultaneously.
Surcharge tiers
| Inventory age | Surcharge / cu ft | Cost per 0.15 cu ft unit | vs. previous tier |
|---|---|---|---|
| 0–180 days | $0.00 | $0.00 / mo | baseline |
| 181–270 days | $0.50 | $0.08 / mo | — |
| 271–365 days | $5.45 | $0.82 / mo | +990% |
| 365+ days | $6.90 or $0.30/unit | $1.04 or $0.30 | +27% |
The 365-day tier uses a floor: Amazon charges whichever is greater between $6.90 per cubic foot or $0.30 per unit. For small products under 0.044 cu ft, the $0.30 per-unit minimum kicks in and costs more than the cubic-foot rate.
Example: 100 units aging through three tiers
100 units of a standard-size product, each 0.15 cu ft (8 × 6 × 5 inches). Product cost: $7 per unit ($700 total). Sent to FBA on January 1. None sell. Here is the surcharge exposure at three checkpoints (regular monthly storage is extra):
| Checkpoint | Age tier | Surcharge / unit / mo | 100-unit monthly cost |
|---|---|---|---|
| Day 200 (late July) | 181–270d | $0.08 | $7.50 |
| Day 300 (late Oct) | 271–365d | $0.82 | $81.75 |
| Day 400 (early Feb) | 365+ | $1.04 | $103.50 |
At the 271-day tier, surcharges alone cost $81.75 per month on a $700 inventory investment. That is 11.7% of the inventory value consumed every month, just in surcharges, on top of regular storage. By month 9 of surcharges (roughly day 450), you have paid more in surcharges than the inventory was worth. A removal order at $0.97 per unit ($97 total) would have saved $700+ in cumulative surcharges.
The 271-day cliff
The single most expensive day in FBA inventory management is day 271. The surcharge jumps from $0.50 to $5.45 per cubic foot overnight. There is no gradual ramp. Sellers who track inventory age weekly and set alerts at day 120, 150, and 170 have time to run promotions, create removal orders, or initiate liquidation before hitting this cliff.
Aged inventory also drags down your IPI score by increasing the excess inventory percentage. A low IPI (below 400) triggers restock limits, which restricts how much new, fast-selling inventory you can send in. The result is a compounding problem: slow inventory occupies space that could hold profitable inventory, and the IPI penalty makes it harder to send in replacements.
Common mistakes
- Assuming the surcharge still starts at 271 days. Amazon moved the threshold to 180 days. Sellers using the old timeline miss the first three months of surcharges entirely, which adds up to $0.24 per unit (0.15 cu ft) before they even notice.
- Not tracking inventory age at the SKU level. A catalog-wide average age means nothing. One SKU at 300 days and another at 30 days show an average of 165, which looks safe. But the aged SKU is already in the $5.45 tier.
- Waiting for the surcharge to show up on invoices before acting. By the time you see the charge, you have already paid for that month. Set alerts at 120 days to start planning: run a sale, create a removal order, or list on a liquidation marketplace. Reacting at 180 days is too late for anything except damage control.