Amazon's Inventory Performance Index is a score between 0 and 1000 that measures how efficiently you manage your FBA inventory. It directly affects how much storage space Amazon gives you. If your score drops below the threshold (which Amazon adjusts periodically), your storage limits get reduced — and that can seriously constrain your ability to send stock in, especially during peak season.
What Affects Your IPI Score
Four main factors contribute to your score. Excess inventory — products that Amazon estimates will take more than 90 days to sell based on current sales velocity. Stranded inventory — stock in Amazon's warehouse that is not connected to an active listing. FBA sell-through rate — how quickly you sell inventory relative to how much you send in. And FBA in-stock rate — how often your products are available for purchase versus out of stock.
The biggest drag on most sellers' IPI scores is excess inventory and stranded inventory. These are the two areas where you have the most direct control and can make the fastest improvements.
How to Improve Your Score
Start by fixing any stranded inventory immediately. Go to the Inventory Dashboard in Seller Central and look for the stranded inventory section. Relist products, update listings, or create removal orders for anything that cannot be relisted. Stranded inventory is the easiest win because it costs you storage fees and produces zero revenue.
For excess inventory, either reduce your prices to increase sell-through, run advertising campaigns to boost sales velocity, or create removal orders for stock that genuinely will not sell at any reasonable price. Holding onto dead stock hoping it will eventually sell is the most common mistake. It drags down your IPI and costs you storage fees every month.
Improve your sell-through rate by sending in smaller, more frequent shipments rather than large bulk sends. This keeps your inventory fresh and your sell-through metrics healthy. If a product sells 50 units per month, sending in 200 units at once gives you four months of stock — Amazon sees that as inefficient. Sending 60 to 80 units every month looks much better.
Why IPI Matters for Peak Season
Amazon evaluates IPI scores and sets storage limits before peak season. If your score is below the threshold when limits are set, you may not have enough storage space to stock up for Black Friday and Christmas. This is why managing your IPI year-round matters — it is not something you can fix overnight when you suddenly need more space.
Check your IPI score regularly in the Inventory Dashboard and treat the threshold as a minimum, not a target. The higher your score, the more flexibility you have to scale your business without running into storage constraints.