Important

Fees & Costs

Amazon Low-Inventory Level Fee

Matthieu

4/8/2026

6 min

Summarize with AI

CTO at Nova Analytics

Matthieu oversees product development at Nova Analytics, creating innovative tools that help Amazon sellers make smarter, data-driven decisions to grow their business.

Quick Summary

Amazon charges FBA sellers $0.32 to $2.09 per unit when both 30-day and 90-day supply averages drop below 28 days. Large standard items get the highest penalty
The safe zone is narrow: 28 to 60 days of supply. Below 28 triggers low-inventory fees. Above 60 starts rising storage costs. Above 180 triggers aged inventory surcharges
Exemptions exist for oversize items, new products (first 180 days), and new-to-FBA ASINs. Standard-size products are the primary target
Set reorder points at 35+ days of supply and track velocity by SKU to avoid both penalties

Nova surfaces every Amazon fee, refund, and margin shift in your live P&L, across 21 marketplaces. Explore the live P&L

What's Happening

Amazon's low-inventory-level fee is charging FBA sellers between $0.32 and $2.09 per unit when their inventory drops below 28 days of supply. First introduced in April 2024, the fee has been updated for 2026 with adjusted thresholds that catch more sellers than ever. According to Webgility's analysis, the penalty applies when both your 30-day and 90-day supply averages fall below the 28-day threshold. This is the kind of announcement we flag in our internal review because it changes inputs to the daily P&L. This is the kind of announcement we flag in our internal review because it changes inputs to the daily P&L.

The fee creates a narrow "safe zone" for FBA sellers. Stock too much and you get hit with aged inventory surcharges. Stock too little and the low-inventory fee kicks in. GoAura's 2026 analysis Calls this the "inventory fee trap" with a safe window of roughly 28 to 60 days of supply.

The penalty only applies to standard-size products. Oversize items, new products (first 180 days), and new-to-FBA ASINs are exempt. But for the majority of FBA catalogs, this fee is a real margin killer that most sellers don't notice until it's already on their statement.

Low-Inventory Fee by the Numbers

Maximum Penalty

$2.09

Per unit when supply is critically low

Threshold

28 days

Both 30-day and 90-day averages must be below

Safe Zone

28–60

Days of supply to avoid both fee types

Days of Supply	Fee per Unit (Small Standard)	Fee per Unit (Large Standard)	Risk Level
0–7 days	$0.89	$2.09	Critical
7–14 days	$0.63	$1.50	High
14–21 days	$0.46	$1.11	Moderate
21–28 days	$0.32	$0.78	Low
28+ days	$0.00	$0.00	Safe

Source: Amazon Seller Central. Fee rates are per unit shipped and vary by size tier. Both your 30-day and 90-day historical days of supply must fall below the threshold for the fee to apply.

How the Fee Actually Works

The Dual-Average Trigger

Amazon uses two moving averages: your 30-day and 90-day days of supply. Both must drop below 28 days for the fee to kick in. This means a single stockout doesn't immediately trigger the penalty. Your 90-day average acts as a buffer. But once both averages are below threshold, every unit shipped gets the surcharge until you replenish.

Who's Exempt

New products (first 180 days with FBA), oversize items, and new-to-FBA ASINs are exempt. If you're launching a product, you have a six-month grace period. But once that window closes, the fee applies retroactively to any period where your supply dropped below 28 days.

The Real Cost at Scale

At $2.09 per unit on large standard items, a seller shipping 5,000 units per month with critically low inventory is paying $10,450 in penalties. That's pure margin loss. Even at the lowest tier ($0.32/unit), 5,000 units costs you $1,600/month. These fees stack on top of your regular FBA fulfillment fees.

The Inventory Fee Trap Explained

Days of Supply	Fee Type	Impact
0–28 days	Low-Inventory-Level Fee	$0.32–$2.09/unit on every shipment
28–60 days	No penalty	Safe zone
60–180 days	Rising storage fees	Monthly storage costs increase
180+ days	Aged inventory surcharge	$1.50–$6.90/unit monthly surcharge

The 28–60 Day Sweet Spot

Your target is clear: maintain 28 to 60 days of supply for every standard-size SKU. Below 28 and the low-inventory fee hits. Above 60 and storage costs start climbing. Above 180 and you're paying aged inventory surcharges. Track your days of inventory at the SKU level to stay in this window.

What You Should Do Now

1.
Check your current days-of-supply by SKU
Log into your analytics dashboard and sort by days of supply. Flag any standard-size SKU below 35 days. You want a buffer above the 28-day threshold to account for shipping delays and demand spikes.
2.
Set reorder points at 35+ days of supply
Don't wait until you're at 28 days to reorder. Factor in your supplier lead time, Amazon inbound processing time (currently 5-14 days), and a safety buffer. Your product-level data shows velocity trends that help you time replenishments.
3.
Quantify the fee impact on your margins
Pull your FBA fee reports and look for low-inventory charges. Calculate the per-unit impact on your contribution margin. For some low-margin products, this fee alone can turn a profitable SKU into a loss-maker.
4.
Consider AWD for buffer stock
Amazon Warehousing & Distribution can hold overflow inventory and auto-replenish FBA. This helps maintain the 28-day minimum without over-stocking at FBA rates. Compare costs against the 2026 AWD fee increases to see if it makes sense for your catalog.
5.
Review your new product launch timeline
New ASINs get a 180-day exemption. Plan your inventory ramp during this window. Once the exemption expires, you need to be at 28+ days of supply immediately. Use your custom analytics to build a launch velocity model.

How Nova Helps

Nova's product-level analytics give you the sales velocity and inventory data you need to stay in the 28-60 day safe zone. Track days of inventory by SKU, monitor your per-unit cost breakdown including FBA fees, and spot SKUs at risk of low-inventory penalties before they hit your statement. All across 21 Amazon marketplaces.

Get More Amazon Seller Tips

Subscribe to our newsletter for weekly insights, strategies, and market updates.

Frequently Asked Questions

Common questions about this topic

Amazon's low-inventory-level fee is a per-unit surcharge applied to FBA standard-size products when both your 30-day and 90-day historical days of supply fall below 28 days. The fee ranges from $0.32 to $2.09 per unit depending on your supply level and product size tier.

Amazon calculates your historical days of supply using two rolling averages: 30-day and 90-day. Both must drop below 28 days for the fee to trigger. The fee rate depends on how far below the threshold you are: 0-7 days is the highest tier ($0.89-$2.09/unit), while 21-28 days is the lowest ($0.32-$0.78/unit).

Oversize products, new products in their first 180 days of FBA enrollment, and new-to-FBA ASINs are exempt. The fee only applies to standard-size products that have been in FBA for more than 180 days.

The safe zone is between 28 and 60 days of supply. Below 28 days triggers the low-inventory-level fee. Above 60 days, monthly storage costs start increasing. Above 180 days, aged inventory surcharges kick in at $1.50-$6.90 per unit per month.

Set reorder points at 35+ days of supply to maintain a buffer. Factor in supplier lead times and Amazon inbound processing (5-14 days). Track sales velocity by SKU and use inventory analytics to spot SKUs approaching the 28-day threshold before the fee triggers.

Verified Sources

All information verified from official Amazon sources and trusted industry analysts as of publication date.

Never Miss a Critical Amazon Update

Get breaking news, policy changes, and time-sensitive updates delivered to your inbox.

Deep Dive: Related Guides

For more comprehensive analysis on these topics:

→ Amazon Days of Inventory (DOI)

DOI formula, category benchmarks, color-coded thresholds, and reorder point strategies. The single metric that controls both stockout risk and storage costs.

→ How to Reduce Amazon FBA Fees: 12 Proven Strategies for 2026

Cut your Amazon FBA costs by 15-30% with these 12 actionable strategies. Optimize inbound placement, reduce storage fees, and improve profit margins using proven tactics.

→ Amazon FBA Storage Fees 2026

Every FBA storage fee explained: monthly rates, Q4 surcharges, aged inventory penalties, AWD comparison, and 5 strategies to cut costs by 25-40%.

→ Amazon Seller Fees Explained 2026: Every Fee in One Place

Referral fees, FBA fulfillment, storage, inbound placement, returns, advertising, and 10 more. The complete reference guide to every Amazon seller fee with current rates.