Aging Inventory on Amazon: Why It Matters and How to Track It

"In the world of Amazon selling, success isn’t just about what you sell — it’s about what you don’t sell fast enough." - Nachman Lieser, Founder and CEO of ConnectBooks

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If you’re an Amazon seller, chances are you’re familiar with the thrill of sourcing a hot product, optimizing listings, and watching orders come in. But while sales are exciting, one aspect of the business that often gets overlooked — until it becomes a serious problem — is aging inventory. Effective inventory management is essential for preventing inventory from aging, as it helps sellers control and optimize stock to reduce the risk of slow-moving products.

Aging inventory doesn’t just tie up your capital; it also poses major financial risks, incurs storage penalties, and can even hurt your Amazon account health. Monitoring inventory levels is crucial to avoid excess stock and improve turnover, ensuring your business remains agile and responsive to demand. This article dives into what aging inventory is, why it’s critical to track, the risks of ignoring it, and how tools like ConnectBooks can help Amazon sellers take control of their inventory age and stay profitable.

What Is Aging Inventory?

Aging inventory refers to products that have been sitting unsold in your warehouse or Amazon’s fulfillment centers for a long period of time. In Amazon terms, this often refers to inventory that has been in FBA (Fulfillment by Amazon) storage for more than 90 days, 180 days, 270 days, or 365+ days. Inventory held for 180 days or more is often considered dead stock.

The longer inventory sits, the more it costs you — not just in storage fees, but in lost opportunities and increased risk.

Aging Buckets (Amazon Standards)

Amazon breaks aging inventory into several time-based buckets, known as age categories, which segment inventory by how long it has been in storage:

• 0–90 days: Fresh inventory.
• 91–180 days: Starting to age, potentially incurring higher fees if demand isn’t strong.
• 181–270 days: Middle-aged inventory; risk is increasing.
• 271–365 days: Old inventory; fees go up.
• 365+ days: Stale inventory; subject to long-term storage fees (LTSF) and often represents a financial liability.

Why You Should Care About Inventory Age

Aging inventory increases inventory costs and occupies valuable space in your warehouse, tying up resources that could be used more efficiently elsewhere. Failing to track inventory age can lead to inventory inefficiencies, reducing profitability and operational effectiveness.

Tracking the age of your inventory isn’t just for large-scale operations or accounting nerds. It’s something every seller (from private label to wholesale to arbitrage), must take seriously. Here’s why:

1. Amazon Storage Fees (Especially Aged Inventory Fees)

Amazon FBA sellers are charged monthly storage fees, and once your inventory hits the 271-day and 365-day marks, Amazon increases these fees dramatically. For inventory that is more than 365 days old, Amazon may charge up to $6.90 per cubic foot or $0.15 per unit — whichever is greater. These long-term storage fees (LTSFs) can eat up your profit margin or worse — push you into a loss. Over time, storage costs can accumulate significantly, impacting your overall profitability and making it essential to manage inventory efficiently.

2. Cash Flow Problems

Old inventory ties up your capital. Inventory holding reduces available cash for reinvestment in faster-moving products, limiting your ability to respond to market demand. Every dollar sitting on a shelf is a dollar that’s not being reinvested into faster-moving, more profitable products. Poor inventory turnover can kill your growth potential, especially for smaller sellers trying to scale.

3. Dead Stock and Obsolescence

The longer a product sits unsold, the higher the risk it becomes obsolete, unmarketable, or damaged. Slow moving products are especially at risk of turning into dead stock if not addressed promptly. Trends change, demand shifts, and your “sure thing” can quickly turn into a dusty liability. Dead stock often ends up in removal orders or liquidation at a loss.

4. Impact on IPI Score and Amazon Account Health

Amazon uses the Inventory Performance Index (IPI) to monitor how well you manage inventory. Aging inventory hurts your sell-through rate — a key metric in the IPI formula. Amazon tracks several key metrics to assess inventory performance and account health. A low IPI score can result in storage limits, making it harder to send in inventory for your best sellers.

5. Risk of Discontinuation and Stranded Inventory

As ASINs age and sell-through slows, you risk having your product listing suppressed, deactivated, or discontinued. Worse, you could end up with stranded inventory that you can’t even sell without taking corrective action. Excess stock increases the risk of stranded inventory and potential losses.

How to Track Inventory Age on Amazon

An inventory aging report is a valuable tool for identifying slow-moving or obsolete stock, allowing sellers to take timely action. Aging inventory reports categorize inventory by age brackets, supporting better stock management and helping optimize stock turnover. 

Amazon offers an FBA Inventory Report in Seller Central, which provides basic insights into stock age to help sellers make informed decisions. Here are some pros and cons of this report. 

Pros: The FBA Inventory Report provides data like:

• Number of units by age bracket (0-90, 91-180, etc.)
• Sales velocity
• Inventory Health Score
• Estimated long-term storage fees

Cons: The FBA report only tracks the unit age once inventory arrives at FBA. The FBA report does not know how long the inventory has been in your warehouse before arriving at FBA, and it does not track FBM inventory. This leaves a gap for sellers who sell FBM or on other channels. Here are a few other downfalls to this report:

• Only includes FBA inventory
• Tracks inventory unit quantity, not inventory cost or value
• Data is not real-time and can be difficult to interpret
• You can’t easily tie the data back to actual profit performance
• Not useful for sellers managing multiple SKUs, warehouses, marketplaces, or brands 

Inventory visibility is crucial for effective inventory management, as it enables sellers to monitor stock levels, identify slow-moving inventory, and make better purchasing decisions. That’s where ConnectBooks steps in. 

‍ConnectBooks can provide comprehensive inventory aging of your entire company (not just FBA), from the moment you purchase it until it's sold. The FBA report only tells the unit quantity, opposed to ConnectBooks which shows the inventory value by age for items sitting in all of your warehouses.

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Using ConnectBooks to Track Inventory Age (and Stay Profitable)

ConnectBooks is a powerful Amazon seller analytics tool that connects directly to your Amazon Seller Central account and integrates with accounting platforms like QuickBooks or Xero. As an inventory management software, it is designed to help Amazon sellers manage and optimize their inventory. It simplifies complex data into clean, visual dashboards — including deep insights into your inventory age and value. Managing inventory effectively is crucial to reduce aging stock and improve profitability, and ConnectBooks supports a proactive inventory control strategy by providing real-time insights and automation for better inventory oversight.

Here’s how ConnectBooks makes inventory aging analysis easy and actionable:

1. Inventory Age Tracking at the SKU Level

ConnectBooks gives you real-time visibility into how long each SKU has been in stock. You can see:

• How many units are in each age bracket (0-90, 91-180, etc.)
• Track stock levels and inventory balances across different locations
• Which products are approaching long-term storage thresholds
• Where inventory is located (FBA, FBM, warehouses)
• Your historical inventory turnover rate
• Inventory costs by age

No more digging through spreadsheets or outdated Amazon reports.

2. Profitability by Age Bracket

Knowing your inventory age is important. But knowing how profitable each age group is — that’s where ConnectBooks really shines. ConnectBooks helps sellers track profit margins and gross profit margin by inventory age, making it easier to identify which age groups are impacting overall profitability.

You can break down profitability by SKU and inventory age, helping you answer questions like:

• Am I holding too much stock for a slow-moving product?
• Are my older SKUs still profitable after fees?
• Which age groups contain the most profitable items?
• Which products need price adjustments or marketing support?

3. Integrated Financial Reporting

Most inventory tools show you units and velocity, but they don’t tie directly to your books.

ConnectBooks syncs with accounting software like QuickBooks, letting you track:

• Inventory value by age
• Track inventory valuation and average inventory cost for more accurate financial analysis
• Monitor average inventory and inventory purchases over time
• COGS (cost of goods sold) by product and time period
• Profit/loss impact of aged inventory

This is essential for accurate financial planning, forecasting, and tax prep.

4. Visual Dashboards and Alerts

ConnectBooks provides intuitive dashboards (including a free dashboard) that highlight:

• Aging inventory at risk of long-term storage fees
• Overstocked SKUs
• Underperforming products
• Identification of slow moving items and slow moving SKUs through inventory aging reports and sales data analysis
• Alerts for products with weak sales to help address slow inventory turnover
• Suggested actions based on sell-through

You can also set up alerts for when a product crosses a certain inventory age threshold — say 180 or 270 days — so you can act before fees kick in.

5. Forecasting and Restock Planning

By knowing how quickly (or slowly) your inventory is moving, ConnectBooks helps you:

• Avoid over-ordering products that are aging
• Make smarter restocking decisions
• Use projected demand and accurate demand forecasts to optimize inventory planning
• Align inventory with customer demand and market demand
• Keep inventory lean and cash flow strong

All of this leads to better working capital management and less dead stock.

Strategies for Managing Aging Inventory

Even with the best tools, inventory will age. It’s just part of the game. The key is knowing how to manage it smartly. Effective inventory control and inventory planning are essential components of a successful supply chain strategy, helping to optimize stock levels and reduce aging inventory. Here are a few tips:

1. Implement an Inventory Age Policy

Set internal guidelines such as:

• 90-day rule: If a SKU doesn’t sell within 90 days, review your pricing strategy and marketing. This 90-day time frame is often considered a good inventory age for most products.
• 180-day rule: Consider running a promotion or liquidation strategy.
• 270+ day rule: Prepare for removal, donation, or liquidation to avoid LTSFs.

2. Optimize Listings

Sometimes inventory ages simply because the listing isn’t converting. Reviewing sales data can help identify which listings are underperforming and reveal opportunities to improve conversion rates. Improve your:

• Titles and bullet points
• Images and A+ content
• Keywords (check indexing and ranking)

Also, consider using Amazon’s Sponsored Products or Coupons to drive visibility.

3. Run Promotions or Bundles

To move older stock, consider:

• Lightning Deals
• Coupons
• Product bundles
• External traffic campaigns (micro-influencer campaigns, email marketing, etc.)

The goal is to get the product moving before it hits the next aging tier. These strategies can help generate strong sales and improve inventory turnover.

4. Use Removal Orders Wisely

Sometimes it’s cheaper to pull inventory than to keep paying fees. Use an aged stock report to identify which items have been in storage the longest and should be prioritized for removal. Create removal orders and either:

• Liquidate through Amazon’s liquidation program
• Repackage or refurbish the product
• Sell on other channels (eBay, Walmart, your own site)

Pro tip: Need help expanding to other channels? Use a channel expansion service such as aiCommerce.

5. Monitor in Real-Time with ConnectBooks

Set aside time weekly or monthly to review your aging inventory using ConnectBooks dashboards. In addition, perform regular inventory audits to ensure data accuracy and identify slow-moving stock early. Stay ahead of problems before they turn into expensive write-offs.

Final Thoughts: Don’t Let Aging Inventory Drain Your Profits

Aging inventory is a silent profit killer, slowly draining your cash flow, clogging your IPI score, and eating away at your margins. When inventory sits unsold, carrying costs such as storage, insurance, and risk of obsolescence further reduce your profitability. But with the right mindset, tools, and systems in place — like ConnectBooks — you can keep your inventory healthy, lean, and profitable.

If you’re not actively tracking inventory age today, start now. Your future cash flow will thank you.