Amazon IPI Score in 2026: Fixing Storage Limits and Restock Caps
Amazon tightened the screws on inventory in 2026. The IPI threshold fell, storage allowances shrank, and thousands of sellers woke up to restock caps on their best sellers. Here is what the score actually measures, why holding a 3PL buffer protects it, and how to recover if yours has dropped.
Your IPI score (0 to 1,000) controls how much you can store in FBA. In 2026 the threshold tightened and allowances dropped to about five months of forecasted sales, with ASIN-level restock caps back. The four drivers are excess inventory, sell-through, stranded inventory and in-stock rate. Holding stock at a 3PL and drip-feeding FBA improves three of the four, because you carry less excess in Amazon while staying in stock.
What's in this guide
What the IPI score is
The Inventory Performance Index is a score from 0 to 1,000 that Amazon assigns your account to measure how efficiently you manage FBA inventory. It updates weekly on a rolling recent-performance window. Its real power is that it controls how much inventory Amazon lets you store, and increasingly, how much of any single SKU you can send in.
Why 2026 is stricter
Two things changed and caught sellers out:
- Amazon tightened the storage allowance, from around six months of forecasted sales down to roughly five, and reactivated ASIN-level restock limits on individual SKUs.
- The practical threshold moved, so sellers who felt safe last year suddenly hit storage cuts, blocking restocks of their bestsellers.
The effect is a squeeze: less room in FBA, and penalties that arrive faster.
The four things it measures
The score is built from four inventory metrics:
- Excess inventory, how much overstock is sitting in FBA.
- Sell-through rate, how fast stock moves relative to what you hold.
- Stranded inventory, units in FBA that have no active listing.
- In-stock rate on replenishable ASINs, whether your live sellers stay in stock.
Notice the tension: Amazon wants you fully in stock but not overstocked. That is hard to do if all your inventory has to physically sit in FBA.
How storage and restock caps bite
Drop below the threshold and Amazon limits your total FBA storage, adds overage charges on anything above the limit, and can cap how many units of a specific SKU you may send, even if you have overall capacity. During Q4 the caps tighten further across the board. The result is the worst case: your bestseller is selling, and you cannot restock it.
How a 3PL buffer protects your score
This is where holding stock outside Amazon helps directly. Keep the bulk of your inventory at a 3PL and drip-feed FBA, and you improve three of the four metrics at once:
- Excess inventory drops, because only a few weeks of cover sit in FBA.
- Sell-through rises, because the stock in Amazon turns over fast.
- In-stock rate holds, because you replenish quickly from the buffer.
You get the lean FBA position Amazon rewards without risking a stockout. See the mechanics in our drip-feeding guide, and the fee side in reducing FBA storage fees if you have that.
Recovering a low score
If your score has already dropped:
- Clear stranded inventory, relist or remove units with no active listing.
- Remove genuine excess, send slow overstock to a 3PL rather than paying aged surcharges. See where to send FBA removals.
- Fix in-stock gaps on your movers by replenishing faster, which a buffer makes possible.
Recovery takes a few weeks because the score is a rolling average, so the sooner you move excess out and tighten replenishment, the sooner the caps lift.
Want a buffer set up so your IPI stops dictating your sales? See our US warehouse and fulfillment service or get a quote.