Amazon Inventory Management:
Never Stock Out Again

Good Amazon inventory management is invisible — products stay in stock, fees stay low, and nobody thinks about it. Bad inventory management shows up twice on your P&L: once as missed sales during stockouts, and again as storage fees on the overcorrection order. Here's the system that keeps you off that seesaw in 2026.

What Poor Inventory Control Actually Costs

• Stockouts: lost sales are the visible cost; the invisible one is rank decay — the algorithm reallocates your position to in-stock competitors, and recovering it means paying for the same rank twice
• Overstock: monthly storage fees, aged-inventory surcharges that escalate sharply after 180+ days, and capital frozen in slow movers
• Emergency responses: air freight to cover a gap typically costs 3–5x sea freight — a self-inflicted margin cut

The Reorder Point: Three Numbers That Run Everything

Reorder point = (daily sales velocity × total lead time in days) + safety stock.

1. Velocity: use a 30-day average, weighted for trend and season — last year's Q4 curve matters more than last month in autumn
2. Lead time: count everything — production, freight, customs, and Amazon's receiving delay (which stretches badly in Q4)
3. Safety stock: 2–4 weeks of velocity for stable products; more for long lead times or volatile demand

When stock touches the reorder point, you order — not when it “feels low.” This single habit prevents most stockouts we see in audited accounts, and stockouts feature heavily in our ten costliest seller mistakes.

IPI Score and Capacity Limits

Your Inventory Performance Index (IPI) is Amazon grading how well you balance stock — excess inventory, sell-through, stranded inventory and in-stock rate. It matters because it drives your FBA capacity limits: strong scores earn room to grow, weak scores literally cap how much you can ship in.

• Keep sell-through healthy: aim to turn inventory every 60–90 days
• Fix stranded inventory weekly — it's pure dead weight against your score
• Clear excess with coupons or Outlet deals before aged surcharges bite
• Protect in-stock rate on your best sellers above all else

Storage Fee Traps to Avoid

Monthly storage fees roughly triple in Q4, and aged-inventory surcharges compound the longer stock sits. The traps: shipping a year of inventory to “save” on freight, oversize products whose storage math never worked, and letting a failed product sit instead of liquidating it. Every fee line is detailed in the 2026 fee breakdown — model storage into unit economics before ordering, not after.

The Weekly 20-Minute System

1. Check days-of-stock on every active ASIN against its reorder point
2. Review inbound shipments for receiving delays
3. Clear stranded and fix any suppressed listings
4. Flag anything under 30 days of stock for action, anything over 120 for clearance planning

Twenty minutes weekly beats a crisis quarterly. If you'd rather never think about it, inventory planning is part of our full account management for US and Canadian brands.

Frequently Asked Questions