Your Amazon IPI (Inventory Performance Index) score is one of the most misunderstood — and most consequential — numbers in your Seller Central account. Drop below the threshold and Amazon restricts how much stock you can send to their fulfilment centres. For high-volume FBA sellers, that means stockouts, lost ranking, and missed revenue during peak periods.
In this guide we explain exactly what IPI measures, what the current threshold is, the four levers that move the score, and seven concrete actions you can take this week to push it up.
What Is the Amazon IPI Score?
The Inventory Performance Index is a score from 0 to 1,000 that Amazon uses to measure how efficiently you manage your FBA inventory. It is updated weekly and visible in the FBA Inventory section of Seller Central under Inventory → FBA Inventory → Inventory Performance.
Current threshold (2026): Sellers with an IPI score below 400 face storage volume limits on each storage type (standard-size, oversize, apparel, footwear). Sellers above 400 receive unlimited FBA storage (subject to Amazon’s standard capacity management policies).
The score is calculated as a rolling 12-week average, which means a bad week has less impact than you might fear — but consistently poor inventory hygiene compounds quickly.
IPI Score Bands
The Four Levers That Drive Your IPI Score
Amazon does not publish the exact formula, but based on seller data and Amazon documentation, the IPI score is driven by four measurable factors:
1. Excess Inventory
Units Amazon classifies as “excess” (over 90 days’ supply on hand). Reduces your score most aggressively. Fix with removals, liquidations, or price cuts to accelerate sell-through.
2. Sell-Through Rate
Units sold and shipped in the past 90 days divided by average FBA inventory. Low sell-through means slow-moving stock. Run ads, lower price, or use deals to improve.
3. Stranded Inventory
FBA units with no active listing (suppressed, inactive, or pricing error). These still incur storage fees but generate no sales. Check the Stranded Inventory report weekly.
4. In-Stock Rate
How often your top-selling ASINs are in stock. Amazon rewards sellers who maintain availability on their best performers. Running out of stock on a top ASIN hurts your IPI and your organic rank.
7 Ways to Improve Your IPI Score This Week
- 1Fix stranded inventory immediately. Go to Inventory → Fix Stranded Inventory in Seller Central. Relist suppressed ASINs, fix pricing errors, or remove units. Even a handful of stranded units drags the score disproportionately.
- 2Create removal orders for aged stock. Units sitting over 365 days are costing you in aged inventory surcharges and hurting your IPI. Create a removal order or enrol in the Liquidations programme to convert dead stock to cash.
- 3Run lightning deals or coupons on slow movers. Even a 15–20% discount can accelerate sell-through enough to push units out of the “excess” category within 2–3 weeks.
- 4Use the FBA Inventory Age report. Filter for items with 180+ days’ supply. These are your IPI killers. Prioritise actions on this specific cohort rather than trying to fix everything at once.
- 5Optimise your reorder quantities. Over-sending is as dangerous as running out. Use Seller Central’s Restock Recommendations (based on your sell-through rate) rather than sending large speculative shipments.
- 6Enrol slow-moving items in FBA Liquidations. Amazon sells excess units through its liquidation channels and credits you a recovery rate (typically 5–20% of average selling price). Better than paying months of storage fees.
- 7Lower your FBA shipments temporarily if over-limit. If you’ve already hit a storage limit, pause shipments on low-velocity ASINs and focus capacity on your top sellers. This directly improves sell-through rate across the board.
Set Up a Weekly IPI Monitoring Routine
The IPI score updates every Sunday. Build a simple weekly checklist:
- Check IPI score in FBA Inventory dashboard
- Review Stranded Inventory report — fix any new issues same day
- Check Inventory Age report — flag any new items crossing the 90-day mark
- Review restock recommendations for top 20 ASINs — adjust shipment quantities
- Check sell-through rate trend — if declining, run a promotion on affected ASINs
How long does it take to improve your IPI score? Because it is a 12-week rolling average, you will typically see meaningful movement within 3–4 weeks of taking corrective action. Sellers who fix stranded inventory and clear excess stock aggressively often recover 50–100 points within a month.
What Happens If You Hit a Storage Limit?
If your IPI drops below 400, Amazon notifies you (usually 6–8 weeks before the limit applies) and assigns a maximum storage volume per storage type. If you exceed that limit, Amazon may refuse new shipments or charge an overage fee of £10 per cubic foot per month on the excess.
The most common impact is stockout on top sellers — you can’t send replenishment stock fast enough. This triggers a ranking drop that can take weeks to recover from. Preventing this is far easier than recovering from it.
Common IPI Questions
Does IPI affect my product rankings?
Not directly. But a low IPI leading to stockouts absolutely affects organic rank. Running out of stock on a top ASIN often causes a significant and lasting ranking drop that only recovers slowly after restocking.
Can I check my IPI score history?
Yes. Seller Central shows your IPI score history over time in the FBA Inventory Performance dashboard. You can see how actions you took correlated with score changes.
Is IPI the same as the Capacity Manager?
No. Amazon’s Capacity Manager is a separate system that lets you request additional capacity above your base limits, using performance credits. Your IPI score influences your base capacity allocation; Capacity Manager lets you bid for more on top of that.
The Bottom Line
A healthy IPI score above 500 gives you unlimited FBA storage and effectively removes one operational constraint from your business. Getting there requires consistent inventory hygiene: fix stranded inventory weekly, remove excess stock aggressively, and avoid over-shipping on slow-moving ASINs.
If your IPI score is currently below 400 and you’re unsure which lever to pull first, the fastest wins are usually stranded inventory fixes (same-day impact) and removal orders for aged stock (3–4 week score improvement). Start there.