There is a number in the background that decides how much stock you are allowed to store at Amazon at all, and many sellers are barely aware of it until something goes wrong: the IPI score. If it falls below a certain threshold, your storage limits shrink, your fees can rise and your availability suffers, which in turn costs rankings that are hard to win back. This article explains what the IPI score measures and how to raise it deliberately.

What the IPI score is

IPI stands for inventory performance index. It is a value on a scale (usually 0 to 1,000) that Amazon assigns to every FBA seller. It reflects how efficiently you use your storage space relative to your sales. Put simply: Amazon wants its warehouse filled with goods that actually sell, not with shelf-warmers. The IPI is Amazon's judgement on how well you manage exactly that.

Above the applicable threshold you usually have unlimited or generous storage capacity. Below it, restrictions follow.

The four factors that drive the score

The IPI is made up of several components. These four weigh heaviest:

  1. Excess inventory: too much stock relative to how fast it sells pushes the score down. Capital tied up in goods sitting still is, from Amazon's point of view, inefficiently used space.
  2. Sell-through rate: how many units you sell relative to average stock over a period. High turnover means a good score.
  3. Stranded inventory: goods sitting in the warehouse that cannot be sold because of a listing problem (a deactivated offer, for instance). Such stock pulls the score down.
  4. In-stock rate: how reliably your well-selling products are available. Frequent stockouts hurt both revenue and the score.

Why the score falls

Typical causes are unbalanced order quantities (too much bought at once), seasonal goods left over after the season, forgotten stranded stock from listing errors, and products that simply do not sell but take up space. It is often a combination: a few slow ASINs with high stock and one or two stranded listings are enough to push the score down noticeably.

How to raise the IPI score

The score does not react overnight, but it can be lifted systematically:

  • Reduce excess inventory: deliberately lower the stock of slow-moving products, through promotions, bundling or clearance. Plan future resupply in smaller and more frequent batches rather than rarely and in bulk.
  • Fix stranded stock at once: check the stranded inventory report regularly and reactivate or remove the affected units. That works fastest, because it is often a matter of a few clicks.
  • Secure availability: put a reliable resupply plan in place for your top sellers so they do not run out.
  • Raise sell-through: improve the listings and advertising of your existing products, so that the stock you have turns over faster.
  • Remove dead inventory: what permanently does not sell should be liquidated or removed, rather than continuing to pay storage costs and an IPI penalty for it.

Patience and routine

The IPI is not a value you repair once. It is a continuous discipline: check stock regularly, fix stranded units, plan resupply in measured amounts. Turn that into a weekly or fortnightly routine and you never get near the critical threshold in the first place.

In short

The IPI score is more than an abstract metric, because it decides your access to Amazon's warehouse and with it your ability to grow. Whoever controls excess inventory, fixes stranded stock quickly, secures availability and keeps sell-through high holds the score steady in the green. That is less work than repairing restricted storage limits after the fact, and it protects your rankings and your cash flow along the way.