IPI frequently asked questions

This page provides answers to common questions regarding the Inventory Performance Index (IPI).

How is IPI calculated?

IPI score measures how efficient and productive you are in managing your FBA inventory. Multiple factors could influence your IPI score, however, the most important ones are based on your actions: 1) maintain a balanced inventory level between sold and on-hand inventory and avoid excess inventory (overstock), 2) avoid long-term storage fees, 3) fix listing problems, and 4) keep your most popular products in stock at the right levels to meet customer demand and maximize customer satisfaction.

Your IPI score is designed to represent your overall inventory performance and considers both your recent and long-term inventory performance. When you take actions to improve your inventory efficiency, these actions can take time to result in IPI improvements. IPI is built to account for seasonality or unexpected disruptions in your business, allowing your long-term inventory performance to serve as your safeguard and prevent your IPI score from short-term fluctuations. This gives you more time to adjust your business and manage your inventory more efficiently in different circumstances.

What’s the best way to improve my IPI score, and what should I prioritize first?

While every sellers’ business is different, we recommend the following general guidelines to manage your inventory performance:

1. Improve your 90-day rolling sell-through by maintaining a sell-through that places you in the green (or “good”) range year-round. Visit the Inventory Age page to see recommendations on your inventory. You can filter by inventory age ranges or sort the FBA sell-through column to see products with the lowest sell-through. The two main ways to improve sell-through are to increase sales in relation to your on-hand inventory or to remove inventory that is not selling.
2. Reduce your excess (overstock) inventory. A good guideline to avoid excess inventory is to maintain enough inventory to cover between 30-60 days of your expected sales. Visit Manage excess inventory to see recommended actions on products that are aged and overstocked. Use Amazon Outlet to sell your overstocked and out-of-season products. On the Manage excess inventory page, select the recommendation filter Create Outlet Deal to see products that are eligible for Amazon Outlet. In addition, you can use Multi-Channel Fulfillment to sell your inventory on other sales channels such as your own website.
3. Reduce or avoid long-term storage fees by removing inventory before it reaches 365 days. You can set up your account to automatically remove aged inventory.
4. Fix listing problems in a timely manner. Regularly check your Stranded inventory percentage. Stranded inventory means you have sellable products in an Amazon fulfillment center with no active listing, and therefore cannot be sold to customers. If you have inventory that is incurring fees without the possibility of sales, this can reduce your IPI score, so it is important to fix listing issues quickly.

Why should I improve my IPI score if my score is below the threshold for the storage limit cycle and I'm subject to storage limits?

As IPI measures the efficiency and productivity of your FBA inventory over time, higher IPI scores usually indicate that you are managing your inventory more efficiently, thus optimizing your sales and minimizing your storage costs.

Refer to the question above for the best ways to improve your IPI score.

Do new ASINs affect my IPI score?

New ASINs in their first 90 days don’t affect your IPI score.

Are removals or liquidations included in IPI?

Once a removal order or liquidation request is placed, the inventory is no longer considered in your IPI score. Remember that actions taken today, like a removal order, will take time to reflect in your IPI score.

I reached the IPI score threshold after score check. Can my storage volume limits be removed?

No. There are two score check weeks that we announce where we evaluate to determine your storage volume limits. You will need to reach the required IPI threshold during one of these score check weeks to be exempt from storage volume limits for the following period. Your current volume limits remain in effect until the new period starts. We encourage you to take actions to maintain your IPI score in time for the next storage volume limit cycle.

How do I know which IPI score is used to determine my storage volume limits?

We will inform you four- to eight-weeks prior to the new period limit going into effect what the IPI threshold will be and which IPI score check weeks we use to evaluate if you will be subject to storage volume limits. You can check your IPI scores for the current and past weeks on your Inventory Performance dashboard. The week that applies to your current score is shown just above your score, and you can view past weeks by clicking the Show details link below your score

How are storage limits determined?

Visit the FBA inventory storage limits Help page for more information.

Why is my product showing as excess after being recently sent to a fulfillment center if I plan to sell it over the next 100 days?

In calculating IPI, we consider an item excess or overstock if it has over 90 days of supply based on the forecasted demand.

How does my FBA in-stock rate affect my IPI?

Your in-stock rate indicates in general how well you replenish your inventory to meet the demand of customers. The in-stock rate itself is not a direct input into your IPI score and a low in-stock rate does not negatively impact IPI, unless your most popular products consistently go out of stock, and the products that remain in-stock have low sales, are aged, or overstocked.

How does flagging an ASIN as non-replenishable affect my IPI score?

Marking a listing as non-replenishable does not impact your IPI score. It simply removes the ASIN from your FBA in-stock rate calculation to keep it accurate, allowing you to keep your in-stock rate up to date. Your on-hand inventory performance affects your IPI score.

How can I improve my sell-through rate?

The two main ways to improve sell-through are to increase sales in relation to your on-hand inventory or to remove inventory that is not selling. To improve sales, consider your pricing and where applicable create sales, improve keywords, advertise with Sponsored Products, or use Multi-Channel Fulfillment to sell your inventory on external channels.

How is the FBA sell-through rate calculated?

Sell-through rate is updated daily based on the past 90 days of shipped units and average inventory over that same period. We encourage you to try to maintain a sell-through rate in the green (or “good” rating) year round.

Your FBA sell-through rate is your units sold and shipped over the past 90 days divided by the average number of units available at fulfillment centers during that time period. We calculate your average units available by taking a snapshot of your inventory levels today and 30, 60, and 90 days ago, then we average those numbers. For example: You shipped 120 units in the past 90 days, and you had an average of 80 units available during that time period. Your sell-through rate would be 120/80 = 1.5, as shown below.

Average available inventory = (50 + 40 + 150 + 80) / 4 = 80 units

Sell-through rate = 120/80 = 1.5

Why don’t I have an IPI score?

An IPI score is available only if you have a Professional selling plan, inventory at a fulfillment center, and recent account activity. If you are new to FBA or have not been active in the past 13 weeks, you may not have an IPI score until more data becomes available. If you only use FBA for Multi-Channel Fulfillment and do not sell in Amazon’s store, you also may not have an IPI score.