sellershortsAmazon IPI Score and Storage Limits Explained
Your IPI score is Amazon's read on how well you manage FBA stock. It is one of several things that shape how much space you get, and Amazon does not publish a pass mark.
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Quick Answer
IPI stands for Inventory Performance Index, and Amazon describes it as a measure of how efficiently you manage your FBA inventory, similar to a credit score for your stock. It matters because Amazon says your FBA capacity limits are influenced by IPI alongside other factors like sales forecasts, shipment lead time, and fulfillment center capacity. Amazon does not publish a required score, so check your own dashboard.
- IPI is Amazon's efficiency read on your FBA inventory
- Capacity is a monthly cubic-foot limit, not a unit count
- IPI is one input into that limit, not the only one
- Amazon publishes no threshold number, so the 400 figure is community consensus
IPI is one of the most argued about numbers in Amazon selling, mostly because people quote thresholds Amazon has never published. That confusion costs sellers real money when they panic about a score instead of fixing the stock behind it.
This guide separates what Amazon actually states from what the seller community repeats, and then gives you the practical work that moves the number either way.
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What the IPI score actually is
IPI is Amazon's scorecard for how well you run your FBA inventory. Amazon itself uses the credit score comparison, which is a useful way to think about it.
Like a credit score, it is a rolling summary of behavior rather than a snapshot. It rewards stock that moves and punishes stock that sits, gets stuck, or runs out. And like a credit score, it goes up slowly and can drop faster than you would like.
The point of the score, from Amazon's side, is space allocation. Fulfillment center capacity is finite. Amazon would rather give that space to sellers whose units sell than to sellers whose units sit.
What Amazon actually states
It is worth separating Amazon's own published statements from the wider commentary, because most confusion comes from mixing the two.
| Claim | Source status |
|---|---|
| IPI measures how efficiently you manage FBA inventory | Stated by Amazon |
| Amazon compares IPI to a credit score for inventory | Stated by Amazon |
| Capacity limits are influenced by IPI plus other factors | Stated by Amazon |
| Those other factors include sales forecasts, shipment lead time, and fulfillment center capacity | Stated by Amazon |
| Capacity is a monthly cubic-foot limit in Capacity Manager | Stated by Amazon |
| You can request more space with a reservation fee | Stated by Amazon |
| Scored 0 to 1000, updated weekly | Community consensus |
| Built from four inputs | Community consensus |
| Threshold of 400 | Community consensus, sources conflict |
Everything in the bottom three rows is widely agreed and probably right, but it is not Amazon policy you can quote. Your own dashboard is the only source that is definitely current for your account.
The four inputs, and what each one means
The IPI score is commonly cited as being built from four measures. Amazon does not publish the formula or the weights, so treat this as the community model.
- Excess inventory. Stock you hold beyond what your sales rate justifies. Old units sitting in a fulfillment center are the classic drag on this score.
- Sell-through rate. How fast your stock leaves relative to how much you hold. Fast movers help, slow movers hurt.
- Stranded inventory. Units in a fulfillment center with no active sellable listing attached. They cost storage and generate zero sales.
- In-stock rate. Whether your selling products are actually available. Running out is treated as poor management, not thriftiness.
Notice the tension built into this. Excess inventory pushes you to hold less. In-stock rate pushes you to hold more. The score rewards accuracy, not caution in either direction.
The threshold question, answered honestly
Amazon does not publish a required IPI score, and any article that states one as fact is quoting the seller community, not Amazon.
The number you will see most often is 400. That figure is widely repeated, but sources conflict, partly because Amazon has changed thresholds in the past and partly because different marketplaces and periods have had different rules.
Here is the practical position to take:
- Do not plan around a number from a blog. Including 400, and including this article.
- Open your Seller Central dashboard. It shows your current score and what Amazon expects from your account right now.
- Treat the trend as more useful than the number. A score climbing from 380 is a healthier signal than one falling from 520.
- Fix the underlying stock problems anyway. Excess and stranded inventory cost you money whether or not they cost you space.
How FBA capacity limits actually work
Your capacity limit is a monthly allowance measured in cubic feet, not a count of units. That distinction matters more than most sellers realize.
Because it is volume based, a pallet of light bulky goods eats your allowance far faster than the same value in small dense items. Two sellers with identical revenue can have completely different capacity pressure depending on what they sell.
Amazon states that the limit is influenced by IPI plus other factors. The ones Amazon names are:
- Your sales forecasts. Amazon's expectation of what you will sell, which is why growth periods can loosen the limit.
- Your shipment lead time. How quickly your inbound shipments arrive and get processed.
- Fulfillment center capacity. How much room Amazon has, which is entirely outside your control and tightens near peak season.
So chasing IPI alone will not guarantee more space. It is one lever on a system with several.
Capacity Manager and buying more space
Capacity Manager is the Seller Central tool where your limit lives. It shows your current allowance and it is where you go when the allowance is not enough.
Amazon provides a route to request additional space through a reservation with a fee. That is genuinely useful if you have a proven seller and a real demand spike, because it turns a hard block into a cost you can model.
It is a bad answer to a structural problem. If you are paying for extra space to store stock that is not selling, you are paying twice for the same mistake. Check the current reservation terms in Seller Central, since these mechanics sit behind a login and have changed over time.
How to raise your IPI score
Work each of the four inputs directly. The order below is roughly fastest payoff first.
- Clear stranded inventory this week. Pull the stranded inventory report, find why each listing is inactive, and either fix the listing or remove the units.
- Deal with excess inventory. Discount it, bundle it, run ads on it, or remove it. Leaving it there keeps costing you storage and score.
- Fix your in-stock rate on real sellers. Set reorder points based on lead time plus a buffer, not on gut feel.
- Send in smaller, more frequent shipments. This lifts sell-through and reduces excess at the same time.
- Improve conversion on slow movers. Sell-through is a demand problem as much as a stock problem. Better images, better price, better listing copy all move units.
- Cut the products that never sell. Some stock is not a forecasting error, it is a bad product. Remove it.
Quick wins if your score just dropped
If you need movement fast, these are the highest ratio actions.
| Action | Effort | Why it works |
|---|---|---|
| Fix stranded listings | Low | Usually a listing error, not a demand problem |
| Create removal orders for dead stock | Low | Removes excess inventory drag directly |
| Discount aged units | Low | Converts excess into sell-through |
| Restock proven sellers | Medium | Lifts in-stock rate on items that actually move |
| Rewrite weak listings | Medium | Raises conversion, which raises sell-through |
| Reduce future shipment sizes | Medium | Prevents the excess problem repeating |
Common mistakes
Most IPI damage is self inflicted and repeats every year.
- Sending in a huge shipment before proving demand. This is the single biggest cause of excess inventory.
- Ignoring the stranded report. It is free score, sitting there, and it takes an afternoon.
- Overcorrecting into stockouts. Slashing inventory to fix excess hurts your in-stock rate instead.
- Only looking at the score before peak season. By the time capacity is tight, the damage is already in the history.
- Treating slow sellers as an inventory problem only. Sometimes the listing, not the stock plan, is what is broken.
Myths worth ignoring
Three claims circulate constantly and none of them survive contact with Amazon's own wording.
- A published pass mark of 400. Amazon publishes no threshold. The number is community consensus and sources disagree.
- IPI alone sets your storage limit. Amazon explicitly says capacity is influenced by IPI plus sales forecasts, lead time, and fulfillment center capacity.
- An exact formula with published weights. The four input model is widely agreed, but Amazon has never published how the score is calculated.
Conclusion
IPI is Amazon's efficiency read on your FBA stock, and it feeds into a capacity system that also weighs your sales forecasts, your shipment lead time, and Amazon's own available space. Nothing about that changes if you memorise a threshold, because Amazon does not publish one.
Do the work instead. Clear stranded units, remove dead stock, keep real sellers in stock, and send in quantities that match demand. Where slow sell-through is really a conversion problem, our Amazon Listing Optimizer rebuilds the listing in one run. Next reads: FBA vs FBM compared, Amazon seller fees in 2026, and the five account health metrics.
References
Frequently asked questions
What is the Amazon IPI score?
IPI stands for Inventory Performance Index. Amazon describes it as a measure of how efficiently you manage your FBA inventory, and Amazon itself compares it to a credit score for your inventory. A higher score means Amazon sees your stock as well managed. A lower score means Amazon sees waste, such as stock that is not selling or units that cannot be sold at all.
What IPI score do I need?
Amazon does not publish a threshold number. The figure most often repeated online is 400, but that is community consensus and different sources disagree, partly because Amazon has changed the number in the past. The only reliable answer is the one on your own dashboard in Seller Central, which shows your current score and what Amazon expects from your account.
How is the IPI score calculated?
Amazon does not publish the formula. It is widely agreed that the score is built from four inputs: excess inventory, sell-through rate, stranded inventory, and in-stock rate. It is also commonly cited as scored on a 0 to 1000 scale and updated weekly. Treat all of that as community consensus, and use your own dashboard as the source of truth.
Does IPI alone decide my storage limit?
No. Amazon states that FBA capacity limits are influenced by IPI plus other factors, including your sales forecasts, your shipment lead time, and available fulfillment center capacity. So a good IPI helps, but it is one input among several. Two sellers with the same score can end up with different limits.
What is Capacity Manager?
Capacity Manager is the tool in Seller Central where you see your FBA capacity limit. The limit is expressed as a monthly cubic-foot allowance rather than a unit count. Inside Capacity Manager you can also request additional space by submitting a reservation with a fee, which is how you get more room when your allowance is not enough.
How do I raise my IPI score?
Work on the four inputs the score is commonly built from. Clear excess inventory so old stock stops dragging you down, improve sell-through by sending in quantities that match real demand, fix stranded inventory so every unit is attached to an active listing, and avoid running out of stock on products that sell. All four move in the right direction when you forecast better.
What is stranded inventory?
Stranded inventory is stock sitting in an Amazon fulfillment center that is not attached to an active, sellable listing. It happens when a listing gets deactivated, suppressed, or has a pricing or compliance error. The units exist, they cost you storage, and nobody can buy them. It is one of the fastest IPI problems to fix because it is usually a listing issue, not a demand issue.
What happens if I go over my capacity limit?
Going over your allowance restricts how much you can send in, which is the practical pain. Amazon offers a route to request more space through Capacity Manager using a reservation fee. Check the current overage and reservation terms in Seller Central, because these details sit behind a login and Amazon has adjusted the mechanics over time.
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