Amazon Inventory Performance Index: How to Fix a Low IPI Score in 2026

The Amazon Inventory Performance Index (IPI) is a score between 0 and 1000 that measures how well you manage your FBA inventory. Amazon updates it weekly. If your score drops below 400, Amazon restricts how much storage you can use at its fulfillment centers. During Q4, the threshold rises and limits hit harder. You need a score above 400 to avoid restrictions, and above 500 to have no practical constraints on your storage capacity.

What Is the Amazon Inventory Performance Index?

Your IPI score is calculated from four inputs: excess inventory percentage, sell-through rate, stranded inventory percentage, and in-stock rate for your top sellers. Amazon does not publish the exact weighting, but excess inventory and sell-through rate have the most visible impact based on how the score moves in practice.

Excess inventory is any stock where you hold more than 90 days of supply. Sell-through rate is units sold and shipped divided by the average units on hand over the last 90 days. Stranded inventory is FBA stock that has no active listing tied to it (suppressed listings, deleted ASINs). In-stock rate measures whether your top-selling ASINs have available inventory.

The score updates every week, typically on Sundays. Changes you make to inventory take two to three weeks to reflect in the score because Amazon uses a rolling window. Do not expect immediate results from a single removal order.

Amazon uses IPI to manage warehouse space across its network. A seller with low IPI ties up shelf space with slow-moving stock, which is expensive for Amazon. The storage limit system is the mechanism Amazon uses to push that cost back onto the seller.

What Happens When Your IPI Score Is Low?

If your IPI score falls below 400 at the quarterly evaluation, Amazon assigns you a storage limit measured in cubic feet. The exact limit depends on your score and your sales history, but sellers with scores in the 300-399 range often receive limits 30-60% below their current stock volume. That forces a choice: pay removal fees, pay long-term storage fees, or scramble to sell through excess stock before the limit kicks in.

Storage limits apply across all FBA inventory, not just the product category causing the low score. A low IPI on a single slow-moving ASIN can indirectly block you from sending in fast-moving products for Q4.

Amazon evaluates IPI scores quarterly (around January, April, July, and October). If your score is below threshold at the evaluation date, the storage limit takes effect two weeks later and lasts for the entire quarter. You cannot appeal storage limits caused by low IPI. The only path out is raising your score before the next evaluation.

Sellers who lose FBA eligibility for specific products due to storage limits must either remove that inventory, pay for storage overage at premium rates ($10+ per cubic foot per month), or switch those SKUs to FBM temporarily.

How to Check Your IPI Score

Log into Seller Central. Go to Inventory, then Inventory Performance. The IPI dashboard shows your current score at the top and breaks down each of the four contributing metrics below it. Each metric has a percentage, a status (good, fair, needs attention), and a direct link to the relevant inventory page.

The "Excess inventory" section shows which ASINs have more than 90 days of supply and how much it is costing you in storage fees. The number next to each ASIN is the recommended quantity to remove or liquidate to bring that ASIN back into a healthy range.

The "Fix stranded inventory" section lists ASINs with FBA stock that has no active listing. Each row shows the reason (suppressed, deleted, inactive) and a button to either fix the listing or create a removal order.

The "Improve sell-through" section lists products with low sales velocity relative to stock on hand. It shows units sold in the last 90 days versus current inventory, with suggested actions (lower price, run a deal, advertise).

The "Maintain in-stock inventory" section flags your top sellers that are running low. Low in-stock on high-velocity ASINs pulls your IPI down even when your other metrics are healthy.

7 Steps to Raise a Low IPI Score

1. Remove excess inventory. Go to Inventory Performance and find every ASIN flagged as excess. Create removal orders for the recommended quantities. Removal costs $0.97 per unit for standard items. It is almost always cheaper than long-term storage fees and the IPI penalty that comes with holding dead stock.
2. Run promotions and price drops to improve sell-through. For slow movers you want to keep, cut the price 15-25% and run a Sponsored Products campaign on exact-match keywords for one to two weeks. The goal is velocity, not margin. A burst of sales moves the sell-through needle faster than waiting for organic traffic.
3. Fix stranded listings immediately. Stranded inventory is the fastest win because the fix is often simple. Go to Inventory, then Fix Stranded Inventory. Common causes are: the listing was deleted but stock remains at the warehouse, a product compliance issue caused a suppression, or a pricing error triggered an automated suppression. Fix the root cause and the inventory becomes active again within 24 hours.
4. Avoid sending new shipments during IPI review periods. Adding more inventory right before a quarterly evaluation makes your excess percentage look worse. If your IPI is borderline (400-450), hold shipments for three to four weeks before the evaluation date, let sell-through improve, then resume replenishment after the evaluation passes.
5. Improve in-stock rate on top sellers. Your top 10 ASINs by sales velocity carry disproportionate weight in the in-stock metric. Set reorder alerts in Seller Central based on days of supply: trigger reorders at 45 days of supply to account for lead time plus FBA processing. A single stockout on a high-velocity ASIN can drop your IPI three to five points.
6. Use FBM as a temporary backup for slow movers. If you have ASINs that sell infrequently but you want to keep them available, switch them to Fulfilled by Merchant and pull the FBA inventory. This removes their excess stock from your IPI calculation. You lose the Prime badge, but your IPI improves. Once you clear your backlog and have space, you can switch back to FBA.
7. Set up reorder alerts based on days of supply. Go to Restock Inventory in Seller Central and review the days of supply column for each ASIN. Set minimum stock levels so you receive email alerts when any top-seller drops below your reorder point. Consistent in-stock performance on your best ASINs is one of the highest-leverage IPI actions you can take over a full quarter.

IPI Score Requirements by Quarter

Amazon evaluates IPI scores four times per year. The standard minimum is 400. If your score is below 400 at the evaluation, you receive a storage limit for that quarter.

Q4 (October through December) is the highest-stakes period. Amazon evaluates IPI in early October, just before the holiday rush. Sellers with low IPI going into Q4 receive storage limits at exactly the moment they need maximum capacity. The evaluation uses your score from the previous few weeks, so your September IPI score is what determines whether you have full Q4 storage access.

Storage limits under the IPI system are calculated as a number of cubic feet. Amazon computes the limit based on your score, your category, and your average storage use over the prior year. A seller with a score of 350 and an average storage footprint of 1,000 cubic feet might receive a limit of 400-600 cubic feet. The exact formula is not published, but sellers consistently report that a 50-point IPI difference can mean a 200-400 cubic foot change in the limit.

To avoid Q4 storage limits, target an IPI score of 450 or higher by the end of September. That gives you a buffer against normal weekly fluctuations and ensures you pass the October evaluation with room to spare.

What is a good Amazon IPI score?

A score above 400 avoids storage restrictions entirely. A score above 500 puts you in the range where Amazon considers your inventory management healthy. Most experienced FBA sellers target 450-550 as a practical operating range. Scores above 700 are achievable but require very lean inventory practices that can conflict with maintaining in-stock rates.

How often does Amazon update the IPI score?

Amazon updates the IPI score once per week, typically on Sundays. The score reflects inventory data over a rolling 90-day window, so changes you make today will take two to three weeks to show up meaningfully in your score.

What causes a low inventory performance index?

The most common causes are: too much inventory on slow-selling ASINs (high excess percentage), not selling through stock fast enough (low sell-through rate), having FBA stock without an active listing attached (stranded inventory), and running out of stock on your best sellers (low in-stock rate). Excess inventory and sell-through rate are typically the dominant factors.

Will a low IPI score affect my Q4 storage limits?

Yes. Amazon evaluates IPI in early October to determine Q4 storage limits. A score below 400 at that evaluation results in a storage limit for the full Q4 quarter. This is the single most costly consequence of low IPI because it restricts inventory right when holiday demand peaks.

How long does it take to improve IPI score?

Expect two to four weeks to see meaningful improvement after taking action. Amazon uses a 90-day rolling window, so your score reflects a blend of past and recent behavior. A large removal order today will start moving the score in two weeks and show full impact after about six weeks.

Can I appeal Amazon storage limit restrictions?

No. Storage limits from low IPI scores are not appealable. Amazon's policy is that the limit is a direct result of the score, and the score is calculated from your own inventory data. The only path to removing the limit is raising your IPI score before the next quarterly evaluation.

Does IPI affect sponsored ads performance?

Not directly. IPI does not feed into ad auction rankings. However, if low IPI leads to storage limits that cause stockouts, those stockouts will pause your ads automatically (Amazon pauses ads when an ASIN has no available inventory). The connection is indirect but real: poor IPI management leads to supply disruptions that kill ad campaigns at the worst possible times.