One Amazon fee change can quietly reduce your margin on every unit you sell: and if you respond by over-ordering, your cash may end up trapped in inventory before Q4 even begins.

As of September 1, 2026, Amazon’s expanded low-inventory surcharge is affecting additional FBA subcategories and product variations. At the same time, inbound placement fees have increased for sellers using single-node or minimal-split shipment options.

If you avoided the fee last quarter, that does not mean your account is protected today.

Previously exempt SKUs may now be affected. Sellers who do not review their inventory strategy may face a painful combination of low-inventory fees, lost sales, higher placement costs, or unnecessary storage expenses.

Fear not, though. This is manageable when you understand the numbers and respond carefully.

I’m Francis Mari, and I help Amazon sellers review account risks, manage compliance, and protect their businesses from avoidable disruptions. In this article, I’ll explain what this change means and how I can help you make the right decision for each FNSKU.

1. The September 1 Expansion Changes Which Products Are at Risk

Amazon’s low-inventory-level fee is designed to encourage sellers to maintain inventory levels that support fast delivery across its fulfillment network.

The expanded structure now reaches additional FBA subcategories, including relevant bulky product tiers. The fee is evaluated at the FNSKU level, meaning individual variations can be assessed separately rather than relying only on the parent ASIN.

That distinction is crucial.

A parent ASIN may appear healthy overall while one popular size, color, or configuration is running dangerously low. That specific FNSKU may be charged the fee even when other variations have adequate stock.

Amazon generally evaluates whether an FNSKU’s inventory falls below a 28-day demand threshold. In practical terms, Amazon compares available inventory against expected customer demand and determines whether the product has enough supply to support its delivery network.

Most sellers assume that looking at the parent ASIN is enough.

It isn’t.

A slow-moving variation may make the overall listing look stable while the best-selling variation is below the threshold. That is how sellers discover the problem only after fees begin appearing in their reports.

For the latest official information, review Amazon’s 2026 US Referral and FBA fee changes summary and its 2026 US FBA fulfillment fee changes.

2. The 28-Day Threshold Is More Complicated Than a Simple Stock Count

The biggest mistake I see sellers make is treating inventory planning as a basic question:

“How many units do I have left?”

That is not the right question.

The better question is:

“How many days of demand does this specific FNSKU represent under Amazon’s current calculation?”

A seller with 500 units may be well stocked if demand is low. Another seller with 500 units may be approaching a fee trigger if the product is selling rapidly.

The calculation becomes even more difficult when you account for:

• Recent sales velocity
• Seasonal demand changes
• Promotional campaigns
• Advertising-driven sales increases
• Units in transit
• Receiving delays
• Variation-level demand
• Forecast changes before Q4
• Available versus reserved inventory

A product that looks safe today may fall below the threshold after a successful promotion or a sudden increase in organic sales.

I recently reviewed an account where the seller had planned inventory at the parent-ASIN level. The total quantity looked reasonable, but the highest-converting variation was moving much faster than the others. The seller was preparing to reorder based on the average, not the actual demand profile.

That approach can create two problems at once: the fast-moving FNSKU may incur low-inventory fees, while slower variations continue accumulating storage costs.

This is why I audit inventory SKU by SKU, not through broad averages.

3. Inbound Placement Fees Make the Margin Calculation Tighter

The low-inventory fee is not the only pressure sellers need to consider.

Amazon has also increased inbound placement service fees for certain shipment configurations, including minimal-split or single-node approaches. The precise cost depends on product size, weight, shipment configuration, and the applicable Amazon rate card.

A lower-complexity inbound plan may appear attractive because it allows you to send inventory to fewer locations. However, that choice can carry a higher per-unit placement cost and may affect how efficiently inventory is positioned across Amazon’s network.

More importantly, the cheapest shipment option is not always the most profitable option.

You need to compare:

1. The inbound placement fee
2. The cost of sending inventory to multiple locations
3. The risk of delays or receiving issues
4. The potential low-inventory surcharge
5. The expected lost sales if a fast-moving FNSKU runs out
6. The storage cost if you send too much inventory

Amazon’s FBA inbound placement service fee guidance should be reviewed alongside the Revenue Calculator and Profit Analytics dashboard.

The trap is assuming that a single inbound decision can be made independently from your inventory strategy.

It cannot.

A shipment plan, forecast, fee structure, and account-health strategy all connect. Treating them as separate issues is a recipe for disaster.

4. Understocking and Overstocking Both Create Expensive Problems

There is no universal answer that says every seller should send more inventory or less inventory.

The correct quantity depends on the economics of the individual FNSKU.

Understocking can lead to:

• Low-inventory-level fees on shipped units
• Lost sales when inventory becomes unavailable
• Reduced delivery availability
• Lower conversion rates
• Missed advertising opportunities
• Emergency replenishment costs
• Pressure to use risky shipment shortcuts

Overstocking can lead to:

• Higher monthly storage fees
• Aged inventory surcharges
• Capital being trapped in slow-moving units
• Discounting pressure
• Removal or disposal costs
• Reduced flexibility before Q4
• Poorer cash flow for new product launches

The math is tight.

If a seller attempts to avoid the fee by sending excessive inventory, that may solve one problem while creating another. You could avoid the low-inventory surcharge but lose margin through storage and aged-inventory costs.

On the other hand, keeping inventory too lean may expose you to fees and stockouts precisely when demand is strongest.

The answer is not panic buying.

The answer is a structured inventory model that considers your demand history, lead times, fees, and risk tolerance.

5. Do Not Try to Game Amazon’s Inventory System

When sellers see fees appear unexpectedly, some try to manipulate the numbers.

I have seen sellers consider:

• Creating fake inbound plans
• Sending “ghost shipments” that are not properly supported
• Over-ordering simply to inflate days of supply
• Splitting inventory without a sound operational reason
• Moving units around to create the appearance of availability
• Using inaccurate shipment data to influence account metrics

These actions can create a much bigger problem than the original fee.

Amazon expects shipment information, inventory records, and account activity to be accurate. Attempts to circumvent policies may be interpreted as deceptive or manipulative behavior and can contribute to a Section 3 suspension.

Most sellers think the danger is only financial.

It isn’t.

A poorly planned attempt to avoid a surcharge can trigger account scrutiny, listing restrictions, or a suspension that interrupts your entire business.

If you have already tried an aggressive workaround and received a warning, deactivation, or policy notification, do not send a rushed explanation. The wording, evidence, and corrective actions need to match the issue Amazon identified.

I provide Amazon reinstatement support for sellers whose accounts or listings have already been flagged.

6. A Proactive Amazon Account Management Service Can Protect Your Q4

September is not the time to wait for the first damaging fee report.

Q4 demand can change quickly, and a strategy that worked during a quieter sales period may not work during peak season. This is especially important if you sell products with long manufacturing lead times, imported inventory, seasonal demand, or multiple variations.

Through my Amazon account management service, I can help you:

1. Audit inventory strategy by FNSKU
   I review the specific variations that drive your sales instead of relying only on parent-ASIN totals.
2. Model the 28-day demand threshold
   I examine inventory levels against recent demand, expected sales, inbound timing, and seasonal changes.
3. Compare understocking and overstocking risk
   The goal is not simply to add more inventory. It is to identify the most commercially sensible range for each product.
4. Review inbound placement decisions
   I help you understand how shipment configuration and placement fees affect your unit economics.
5. Monitor account-health risks
   Inventory issues can connect with listing availability, delivery performance, customer experience, and policy compliance.
6. Build a Q4 compliance plan
   Ongoing oversight can help you respond to fee changes and account signals before they become an emergency.

The objective is simple: protect your margins without putting your account at unnecessary risk.

That is also why proactive account management matters when you want to prevent Amazon suspension. Account stability is not created by reacting to warnings after they arrive. It is built by identifying operational risks early and correcting them before Amazon has a reason to intervene.

7. Your Next Decision Should Be Based on Your Data, Not Fear

Amazon’s September 1 expansion creates a difficult balancing act.

Understock and you may pay the low-inventory fee while losing sales. Overstock and you may pay through storage, aged inventory, and tied-up capital. Use inaccurate or artificial methods to manipulate the calculation and you may turn a fee problem into a policy problem.

The sellers who navigate this successfully will not necessarily be the ones with the largest inventory budgets.

They will be the ones who understand their FNSKU-level numbers and make compliant decisions early.

Amazon’s inventory rules and fee structures are too important to manage through assumptions. If you are unsure which SKUs are exposed, how the 28-day threshold affects you, or whether your inbound plan is still profitable, I can review the situation with you personally.

Amazon fee management is not just about reducing a charge. It is about protecting sales, cash flow, delivery performance, and account health at the same time.

You have two options now: continue guessing as the new fee structure affects more of your catalog: or have your inventory strategy reviewed before Q4 pressure intensifies.

If you need a personalized review, contact me through Mari Marketing. I can help you audit the numbers, identify the risks, and create a compliant plan designed around your actual Amazon business.

Don’t let common mistakes hinder your journey. The right inventory decision today can protect both your margins and your ability to keep selling tomorrow.