IPI (Inventory Performance Index)

Amazon & D2C glossary · Harpy Media

IPI (Inventory Performance Index) is Amazon’s 0–1000 score for how well you manage FBA inventory: how productively your stock turns, how effectively listings convert customers, how well you avoid excess and age-outs, and how steadily popular products stay in stock.

What is IPI?

IPI (Inventory Performance Index) is Amazon’s 0–1000 score for how well you manage FBA inventory: how productively your stock turns, how effectively listings convert customers, how well you avoid excess and age-outs, and how steadily popular products stay in stock.

The score is the lever on your storage permissions. Above the threshold, capacity flows generously, including during peak; below it, storage limits tighten, overage consequences loom, and inbound quantity becomes a scarce resource that can’t keep up with demand. Every attempt to run inventory sloppily now carries a compound cost: fees plus constrained capacity — a throttle on the very availability growth requires.

What the score actually measures (and what moves it)

The components, in practical terms: sales-through and healthy turn (stock that sells — the heavy weight), excess inventory relative to sales (the counterweight — slow and excess stock drags hard, plus aged-inventory surcharges), stranded or unfulfillable stock (the mishaps: pricing errors, suppressed listings, compliance blocks — small counts, outsize damage), and in-stock rate for your best sellers (availability discipline). The actionable hierarchy: heroes in stock (availability fix), excess cleared (deals, bundles, removal — clearing is usually cheaper than the score damage), strandeds resolved (weekly scan of discovery reports; each fix is a quick win), and turnover improved (the seasonal work of forecasting and assortment). None of the levers is exotic — but they only count when someone is actually pulling them.

Managing IPI like a business metric (because it is)

The operating rhythm: check the score with its components weekly (drift is easier to correct early), act on whichever component is furthest off, and plan the calendar around the peak-season capacity cycle (IPI determines holiday storage permissions — so the months before peak are its most consequential). For sellers in a hole: the fastest lifts are usually clearing excess (immediate points from both the excess and sell-through sides) and resolving strandeds — and once above the threshold, the game becomes maintenance via the same monthly inventory reviews the score is really measuring (aging buckets, quadrants, replenishment honesty). Treat the score as a mirror of inventory discipline rather than a game to be gamed — because the behaviours that raise it are exactly the ones that make money.

In practice

A seller enters the pre-peak window at a mediocre score, worried about Q4 storage limits. A 45-day sprint: excess stock moved via a staged deal campaign and bundle consolidation, 23 stranded units resolved (repricing fixes and a suppressed listing), heroes restocked to never go dark through the summer. The score climbs to comfortable territory with capacity to spare into Q4 — and the work that lifted it was, in every line, work the P&L wanted done anyway.

How Harpy Media helps

IPI sits on our weekly client dashboards with components broken out — because capacity permissions in peak season are won in the spring, not the autumn.

IPI FAQ

What is the Inventory Performance Index?

Amazon’s 0–1000 score for FBA inventory management — balancing productive turnover against excess, strandeds, and stockouts; it governs storage capacity permissions.

How do I raise my IPI?

Keep best sellers in stock, clear excess inventory, resolve stranded units, and improve turnover through forecasting and assortment discipline — in that rough order of speed.

Does IPI affect peak-season storage?

Yes — it shapes storage and inbound quantity limits, including the peak preparations that determine how much Q4 stock you can have in the network.