Amazon Inventory Management SOP: Restock, Track, Audit

Why You Need an Inventory SOP

Inventory management is the task that most directly impacts your Amazon P&L, and it's the one sellers most commonly get wrong. A stockout on a product selling 20 units per day doesn't just cost you $600+ in daily lost revenue — it damages your organic ranking, which can take 2-4 weeks to recover after you restock. Excess inventory ties up capital and racks up storage fees that silently eat your margins.

The difference between good and bad inventory management isn't intelligence — it's consistency. Sellers who check inventory systematically on a fixed cadence catch problems with 3-4 weeks of lead time. Sellers who check whenever they remember catch problems when it's too late to avoid the damage. An SOP creates that consistency.

This SOP covers four cadences: daily quick checks, weekly deep reviews, monthly full audits, and quarterly strategic adjustments. Each cadence has specific steps, specific thresholds for action, and specific documentation. For the broader SOP framework, see our complete Amazon SOP guide.

Daily Checks (5-10 Minutes)

The daily check is a quick scan for issues that need immediate attention. It should be the first thing you do each morning — or better yet, automated so it runs before you wake up.

Stranded inventory check: Stranded inventory is stock sitting in FBA fulfillment centers that isn't listed for sale. This happens when a listing gets suppressed, a product is marked as restricted, or a listing update creates an error. You're paying storage fees on products nobody can buy. Check Inventory → Fix Stranded Inventory in Seller Central daily. Any stranded units should be resolved within 24 hours — either fix the listing issue or create a removal order.

FBA shipment receipt verification: When you have inbound shipments, verify that Amazon is receiving the correct quantities. Discrepancies (fewer units received than shipped) need to be flagged immediately — you have a 9-month window to file discrepancy claims, but the sooner you file, the better your documentation. Check Inventory → FBA Shipments for any shipments in "receiving" status.

Suppressed listing scan: A suppressed listing means your product is invisible to shoppers but inventory keeps aging in the warehouse. Check for new suppressions daily and resolve them immediately. Common causes include policy violations in listing content, missing required attributes, and image compliance issues. Our suppressed listing fix guide covers the most common resolution steps.

Velocity anomaly check: Is any product selling significantly faster or slower than its 30-day average? A velocity spike (great news, but restock sooner) or a velocity drop (investigate — did you lose the Buy Box? Did a competitor drop their price? Was a review suppressed?) both require attention. A 30%+ deviation from average velocity should trigger investigation.

Weekly Reviews (30-45 Minutes)

The weekly review is the core of your inventory SOP. This is where you make reorder decisions, catch emerging problems, and ensure nothing is slipping through the cracks.

Days of supply review — all ASINs: Calculate days of supply for every active ASIN: Current FBA Units ÷ Average Daily Velocity (last 30 days). Categorize each ASIN into zones:

• Green (30+ days): Healthy. No action needed this week.
• Yellow (15-30 days): Approaching reorder point. Evaluate whether a reorder is needed based on lead time.
• Red (under 15 days): Urgent. If lead time exceeds remaining days of supply, you're going to stock out. Take immediate action — place emergency orders, consider air freight for critical products, or set up FBM fulfillment as a bridge.

IPI score check: Your Inventory Performance Index affects your FBA storage limits. Check it weekly and track the trend. A declining IPI, even if still above 400, signals that Amazon's algorithm sees issues with your inventory health. The four components that affect IPI are excess inventory percentage, sell-through rate, stranded inventory percentage, and in-stock rate. For a deep dive, see our IPI improvement guide.

Reorder candidates: For any ASIN where days of supply is less than (lead time + 14 days safety stock), initiate a reorder. Calculate the reorder quantity using the formula in the next section. Document the reorder decision: quantity ordered, supplier, expected ship date, and expected FBA arrival date.

Inbound shipment tracking: Review the status of all inbound shipments. Are they on schedule? Has Amazon started receiving them? Are there any receiving discrepancies to investigate? Shipments that take longer than 2 weeks to move from "checked in" to "receiving" may need investigation through Seller Support.

Monthly Audits (1-2 Hours)

Full inventory reconciliation: Compare your FBA inventory records against your own inventory tracking system (whether that's a spreadsheet, an ERP, or Jarvio). Discrepancies indicate lost units, miscounted receipts, or system errors. Any unexplained discrepancy above 1% of total units should be investigated and may qualify for reimbursement claims. Our FBA reimbursements guide covers how to identify and claim these.

Aged inventory review: Pull the Aged Inventory Report from Seller Central. Identify all units approaching or exceeding the 180-day and 365-day thresholds. For each aged SKU, decide on one of four actions: promote (run a sale or coupon to accelerate sell-through), remove (create a removal order to your warehouse for relisting or other channel sales), liquidate (use Amazon's liquidation program — you'll get pennies on the dollar but avoid ongoing storage fees), or hold (only if you have a specific plan to sell through, such as an upcoming seasonal demand spike).

Storage fee analysis: Review your monthly storage fee charges. Are they in line with expectations? Storage fees vary by season (October-December rates are 2-3x higher than January-September) and by product size. If storage fees exceed 5% of revenue for any SKU, that product's inventory strategy needs adjustment — either reduce inbound quantities, increase velocity through promotion, or reconsider whether the product is worth selling.

Reimbursement scan: Review the past 30 days for reimbursement opportunities: customer returns where the buyer was refunded but the item wasn't returned to your inventory, lost or damaged inventory during FBA processing, inbound shipment quantity discrepancies, and overcharged fees. Most sellers leave $1,000-$5,000 per year on the table by not systematically claiming reimbursements.

Quarterly Adjustments

Seasonal velocity adjustments: Update your velocity forecasts based on seasonal patterns. Q4 typically requires 2-3x normal inventory for most consumer products. Q1 post-holiday typically sees a velocity drop of 20-30%. Spring and summer have their own patterns depending on your category. Use last year's quarterly data to build seasonal multipliers for each ASIN.

Supplier lead time verification: Lead times change. Manufacturing capacity fluctuates with demand, shipping routes and transit times vary, and customs processing times can shift. Confirm current lead times with every supplier quarterly. Update your reorder triggers if lead times have changed — an increase from 6 weeks to 8 weeks means you need to reorder 2 weeks earlier.

Safety stock recalibration: Your safety stock buffer should reflect the uncertainty in your supply chain. If your supplier has been consistently reliable (delivery within ±3 days of estimated arrival for the last 4 quarters), you can reduce safety stock to 10 days. If lead times have been variable (±2 weeks), increase safety stock to 21 days. The goal is enough buffer to prevent stockouts without tying up excess capital in inventory that arrives too early.

SKU rationalization: Review your catalog's inventory performance. Are there SKUs that consistently underperform — low velocity, high storage fees, frequent aged inventory issues? Consider discontinuing products that don't justify their inventory carrying costs. Every SKU in your catalog consumes management attention and working capital. A focused catalog of high-performing products is more profitable than a broad catalog with tail SKUs dragging down overall performance.

The Reorder Formula

Use this formula for every reorder decision:

Adjust the formula for known seasonal variations. If you're ordering in August for Q4, use your Q4 velocity forecast (typically 2-3x normal), not your current velocity. Under-ordering for Q4 is one of the most expensive inventory mistakes — by the time you realize you're running low, it's too late to reorder before peak season. See our Q4 calendar for seasonal planning deadlines.

Managing Your IPI Score

Your Inventory Performance Index is a composite score (0-1000) that Amazon uses to determine your FBA storage limits. The four factors and how to influence them:

Excess inventory percentage: Reduce by creating removal orders for slow-moving inventory, running promotions to increase velocity on overstocked products, and avoiding over-ordering relative to demand. Amazon considers inventory "excess" when your supply exceeds 90 days based on forecasted demand.

Sell-through rate: Improve by maintaining healthy velocity across your catalog, removing slow-selling SKUs from FBA, and running promotions on stagnant inventory. Sell-through is calculated as units sold and shipped over the last 90 days divided by average units on hand during that period.

Stranded inventory percentage: Keep at 0% by resolving stranded inventory within 24 hours. Set up daily alerts for new stranded units. Common causes include listing suppressions, policy violations, and incomplete listing attributes.

In-stock rate: Improve by avoiding stockouts on your replenishable products. Amazon weights this toward your higher-velocity and higher-revenue ASINs — a stockout on your best seller hurts your IPI more than a stockout on a slow-moving product. Consistent reorder processes (following this SOP) directly improve your in-stock rate.

Common Inventory Mistakes

Using average velocity without considering trends. A product that sold 10 units/day last month but is trending up to 15 units/day this week will stock out faster than your 30-day average suggests. Check velocity trends, not just averages.

Forgetting Amazon receiving time. Your lead time isn't just manufacturing + shipping. Add 1-2 weeks for Amazon to receive, check in, and make your inventory available for sale. During peak season (October-December), receiving times can stretch to 3-4 weeks.

Over-ordering to "be safe." Excess inventory carries real costs: monthly storage fees, aged inventory surcharges, tied-up capital, and IPI score impact. Order what you need based on data, not anxiety. Your safety stock buffer exists to handle uncertainty — you don't need to double it "just in case."

Ignoring removal order economics. Sometimes the cheapest option is to remove slow-moving inventory and sell it through another channel (your own website, wholesale, liquidation) rather than paying escalating storage fees at FBA. Run the numbers: if storage fees over the next 6 months exceed the cost of removal + the margin you'd lose selling elsewhere, remove the inventory.

Automate the Routine

Here's the thing about this SOP: every check, every calculation, and every alert can run automatically. The daily stranded inventory check, the weekly days-of-supply review, the monthly reimbursement scan — all of it follows rules that an AI agent can execute faster and more consistently than a human. Here's what automated inventory management looks like: