Amazon FBA inventory performance index explained for beginners

If you sell on Amazon FBA, your Inventory Performance Index (IPI) directly affects your storage limits and fees. This guide explains what IPI is, why it matters for sellers and buyers in 2026, how to evaluate it, common mistakes, and practical steps to improve your score. You'll leave with a clear action plan.

Why Amazon FBA Inventory Performance Index (IPI) Matters in 2026

Amazon FBA uses the IPI score to measure how well you manage your inventory. The score ranges from 0 to 1000, and a higher score means you are stocking efficiently, avoiding excess inventory, and reducing storage costs. In 2026, Amazon continues to use IPI to set storage limits for sellers. If your IPI is below the threshold (often 400), you may face quantity limits on your FBA shipments, which can disrupt your sales and increase costs.

For buyers, IPI indirectly affects product availability and pricing. Sellers with low IPI may run out of stock or incur higher storage fees, which can lead to price increases or stockouts. Understanding IPI helps buyers identify reliable sellers and anticipate potential supply issues.

• Storage limits: IPI below threshold can restrict how much inventory you can send to FBA.
• Fee implications: Low IPI may result in surcharges for excess or aged inventory.
• Buyer impact: Stockouts and price volatility affect purchasing decisions.

Key Categories / Types of Amazon FBA Inventory Performance Index (IPI)

The IPI is not a single metric but a composite score based on four factors: excess inventory, sell-through rate, in-stock rate, and stranded inventory. Each factor contributes to your overall score, and understanding them helps you target improvements.

Excess inventory measures the amount of inventory that is not selling as fast as expected, leading to high storage costs. Sell-through rate tracks how quickly you sell through your inventory relative to available units. In-stock rate indicates how often you have products available to ship, avoiding stockouts. Stranded inventory refers to items that are unsellable due to listing issues or other problems.

• Excess inventory: Items sitting in warehouses longer than 90 days.
• Sell-through rate: Units sold divided by units available over a period.
• In-stock rate: Percentage of time you have inventory available for key products.
• Stranded inventory: Stock that is not buyable due to listing errors or damage.

How to Evaluate Amazon FBA Inventory Performance Index (IPI): Criteria and Trade-offs

To evaluate your IPI, access your Seller Central dashboard under 'Inventory Performance'. The score is updated daily, but Amazon calculates it based on your trailing 90 days of activity. A score above 400 is generally considered good, but the exact threshold can change (indicative as of 2026). Aim for 500 or higher to have more flexibility.

When interpreting IPI, consider the trade-offs. For example, maintaining a high in-stock rate may require holding more inventory, which can increase excess inventory risk. Conversely, reducing excess inventory by discounting or removing items may hurt your sell-through rate. Balance is key.

Typical strategies include: reducing excess by creating removal orders or running promotions, improving sell-through by optimizing listings, and fixing stranded inventory promptly. Monitor your 'IPI score history' to see trends and adjust.

• Check your IPI score at least weekly.
• Monitor the four components separately to identify weak areas.
• Use the 'Inventory Performance' dashboard to see recommendations.
• Set a target score (e.g., 450) and track progress monthly.

Common Pitfalls When Dealing with Amazon FBA Inventory Performance Index (IPI)

One common pitfall is ignoring excess inventory for too long. Storage fees increase over time, and aged inventory (over 365 days) incurs additional long-term storage fees. Another mistake is overreacting to a low IPI by slashing prices too aggressively, which can hurt profit margins and set a precedent for low pricing.

Sellers often neglect stranded inventory, thinking it's a minor issue. However, stranded inventory counts against your IPI and is not sellable, wasting storage space. Also, some sellers try to game the system by artificially inflating sales, which Amazon can detect and penalize. Avoid such tactics.

Finally, don't assume IPI is static. It changes based on your actions and seasonality. A high score during Q4 may drop in January if you don't adjust inventory levels after the holiday rush.

• Ignoring aged inventory and long-term storage fees.
• Overdiscounting to improve sell-through, hurting margins.
• Not fixing stranded inventory quickly.
• Attempting to manipulate IPI with fake sales.
• Failing to adjust for seasonality.

Practical Recommendations and Next Steps

Start by downloading your IPI report and reviewing each component. Prioritize actions that have the biggest impact: if excess inventory is high, create removal orders or run clearance deals. If sell-through is low, optimize your listing with better keywords and images. For stranded inventory, resolve listing errors immediately.

Set a schedule to review your inventory performance weekly. Use Amazon's recommended actions in the dashboard. Consider using inventory management software to forecast demand more accurately, reducing excess and stockouts.

For buyers, check seller IPI information if available (some sellers share it), or look for signs like frequent stockouts or high prices. You can also contact sellers to ask about their inventory health.

• Download your IPI report and analyze components.
• Create a weekly review routine for IPI.
• Use Amazon's recommended actions.
• Invest in inventory forecasting tools.
• For buyers: monitor seller stock levels and reviews.

Key Takeaways

The Amazon FBA Inventory Performance Index is a critical metric for sellers, impacting storage limits and fees. By understanding its components, evaluating your score, and avoiding common pitfalls, you can improve your IPI and run a more efficient FBA business. Start by reviewing your current score and implementing the recommendations above. For buyers, staying informed about IPI helps you make smarter purchasing decisions. Remember, IPI policies and thresholds can change, so always check official Amazon updates.

This article is compiled by kuajing168.cn for reference only. Please refer to the official announcements of each platform for the latest policies and rates.