Amazon FBA
What Is IPI (Inventory Performance Index)?
IPI is Amazon's 0 to 1000 score measuring how efficiently you manage FBA inventory. It factors in excess inventory, sell-through rate, stranded inventory, and in-stock levels. Falling below the threshold (typically 400) triggers storage capacity limits and higher fees. A dropping IPI before Q4 can cap your restock exactly when demand peaks.
IPI (Inventory Performance Index) is Amazon's quarterly 01000 score that determines how much FBA storage capacity you get. Drop below the threshold and Amazon caps your inventory, exactly when peak season needs more space.
What goes into the score
- Excess inventory: units sitting in FBA over 90 days
- Stranded inventory: active SKUs without sales (listing issues, suppression)
- Sell-through rate: units sold ÷ average inventory over the last 90 days
- In-stock rate: percentage of replenishable products with positive inventory
Threshold impact
- 700+ IPI: best-in-class, expanded storage benefits
- 500700: healthy range, standard storage
- 400500: warning band, storage growth restricted
- Below 400: storage cap imposed at quarterly review, sometimes severe
Example
A seller carrying 25% excess inventory and 7% stranded across the catalog drops IPI from 580 to 420 in one quarter. At the next review Amazon caps storage at the current level, meaning the peak-season PO they planned cannot be sent in. The cap costs an estimated $300K of Q4 revenue.
The most common mistake
Not building IPI into the forecast. Most FBA forecasts plan inventory and ad spend without checking whether IPI will support the storage need. Track forward IPI (90-day projection) alongside the inventory plan.
Frequently Asked Questions
what is the IPI threshold?
Below 400 triggers storage limits.
what hurts IPI the most?
Excess inventory, stranded inventory, low sell-through.
how do I improve IPI before peak season?
Liquidate excess, fix stranded listings, accelerate sell-through on slow SKUs starting 90 days out.
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