Amazon Inventory Planning and Replenishment Analytics

For Amazon FBA sellers, inventory is uniquely high-stakes:

• Stockouts immediately lose you the Buy Box, drop your BSR, and can take weeks to recover — Amazon deprioritises previously-stocked-out ASINs in search ranking
• Overstocking leads to long-term storage fees (expensive) and ties up working capital
• Demand seasonality is pronounced on Amazon — Q4 (especially November/December) can represent 30–50% of annual sales for some categories

Getting inventory levels right is arguably the most impactful operational challenge for FBA sellers.

In Amazon → Inventory, AskBiz tracks:

• Days of supply: units in FBA ÷ average daily sales rate = days until stockout
• Sell-through rate: units sold in last 90 days ÷ average units in FBA × 100 (Amazon's own metric; below 50% risks storage limits)
• Restock recommendation: suggested units to send based on sales velocity + lead time + safety stock
• Aged inventory alert: units approaching 181 or 365 days in FBA
• Storage utilisation: how close you are to your FBA storage limit

For accurate replenishment recommendations, enter in Amazon → Inventory → Settings:

1. Lead time: days from placing a manufacturing or purchase order to units arriving at FBA. Include supplier lead time + shipping + FBA intake (typically 10–45 days total)

2. Safety stock days: extra days of buffer inventory you want to hold. 30–45 days is standard; increase for seasonal products or unreliable suppliers

3. Order frequency: how often you place replenishment orders (e.g. every 30 days, every 90 days)

With these set, AskBiz calculates: Reorder point = (Average daily sales × Lead time) + Safety stock

Amazon demand is highly seasonal. AskBiz uses last year's sales data by week to create seasonal adjustments to baseline forecasts.

To view seasonal forecast: go to Amazon → Inventory → [ASIN] → Demand Forecast. Toggle between 'baseline' (current velocity extrapolated) and 'seasonal' (adjusted for historical seasonality).

Key planning dates for UK sellers:

• Order Q4 stock by early September (allow for manufacturing + shipping)
• Black Friday / Cyber Monday inventory should arrive at FBA by early November
• January clearance demand for some categories
• Summer peaks for garden, outdoor, and sports categories (order by April)

Amazon charges aged inventory surcharges for units stored 181–365 days and 365+ days. These fees can make marginal-margin products unprofitable.

Strategies to avoid long-term storage fees:

1. Run a promotion: reduce price or add a coupon to accelerate sell-through before the fee kicks in

2. Create a bundle: combine slow-moving stock with a faster seller to deplete inventory

3. Remove inventory: pay the removal fee (£0.25–£1.00) rather than the long-term storage surcharge if the unit economics work out

4. Liquidate: Amazon's liquidation programme pays 5–15 cents on the dollar but is better than long-term storage fees for very slow movers

AskBiz alerts you to at-risk inventory 45 days before it crosses the 181-day threshold at Settings → Alerts → Amazon → Aged Inventory.

Amazon imposes FBA storage limits (Inventory Performance Index or IPI-based limits for larger sellers). If you hit your limit, you cannot send more inventory.

IPI score factors:

• Excess inventory percentage
• Sell-through rate
• Stranded inventory percentage
• In-stock rate

Keep IPI above 450 (Amazon's threshold for unlimited storage on standard-size products). In AskBiz, check your current IPI in Amazon → Inventory → IPI Score and see which factors are dragging it down.