Section 01

The Two Fees Everyone Knows: Referral and Fulfillment

Start with the two that hit every single unit you sell.

The referral fee is Amazon’s commission on the sale. It runs from a few percent up to 45% depending on category, and most categories sit at 15% (Home and Kitchen, Toys and Games, Sports and Outdoors, Office Products, and roughly two dozen more). Some categories run lower, like Consumer Electronics at 8%, and a handful use a tiered structure that charges one rate up to a price threshold and a different rate above it. There is a $0.30 minimum referral fee per item, which only matters on very low priced products. Amazon left referral percentages unchanged for 2026, so if you priced your catalog against the prior year’s rates, that side of the math did not move. Confirm the exact rate for each of your categories on Amazon’s referral fee schedule before you model margin, because the tiered ones catch people off guard.

The FBA fulfillment fee is what you pay Amazon to pick, pack, and ship the unit. This is where 2026 moved. Per Amazon’s 2026 fee announcement, fulfillment fees rose an average of $0.08 per unit on January 15, 2026, which sounds trivial until you multiply it across a full catalog. The fee itself scales by size tier and weight, so the only number that matters is the one for your specific SKU. Pull it from your live rate card rather than a figure from a blog. Products priced under $10 sit in a separate Low Price FBA program and did not see the same increase.

Then the part most operators miss. On April 17, 2026, Amazon added a 3.5% fuel and logistics surcharge on top of every FBA fulfillment fee. It is not a flat cent amount. It is a multiplier. To get your true post April fulfillment cost, take the published fee and multiply by 1.035. On a standard size unit that is roughly a dime or two per unit; on a heavy oversize unit it is a lot more.

What to do this week:

• Repull your fulfillment fee per SKU from the current rate card, then multiply by 1.035. The number in your old spreadsheet is stale by two increases.
• Check which referral tier each SKU actually falls in. Tiered categories move you between rates as your price crosses the threshold, so confirm each one on Amazon’s referral fee schedule.
• Flag any SKU under $10. It qualifies for Low Price FBA and a different, lower fulfillment fee.

Section 02

The Storage Stack: Monthly, Then the Surcharges

Storage is where a healthy P&L quietly bleeds, because it compounds every month the inventory sits.

Monthly inventory storage is charged per cubic foot. Per Amazon’s monthly storage fee schedule, from January through September standard size runs $0.78 per cubic foot per month and oversize runs $0.56. From October through December, both rates roughly triple, with standard size reaching $2.40 and oversize $1.40 per cubic foot. That Q4 jump is the single most predictable fee spike on the calendar, and it is the reason overstocking in September is one of the most expensive mistakes an operator makes.

Then the aged inventory surcharge, which is the fee that catches sellers who launched into a slow category and never trued up their forecast. It stacks on top of the normal monthly storage fee, and it kicks in at 181 days, not 271 the way the old long term storage fee did. Per Amazon’s aged inventory surcharge page, the rate steps up in bands as inventory ages past 181 days, 271 days, and 365 days, and Amazon bills the greater of a per cubic foot or a per unit amount. The exact per band dollar figures live in your Seller Central fee schedule because Amazon revises them, so pull yours there rather than trust a static number. The shape is what matters. It is gentle just past 181 days and brutal past a year.

If your forecasting is what keeps units past these thresholds in the first place, that is the real fix. Our FBA inventory planning guide walks the days of cover math we run on every managed account.

What to do this week:

• Pull your inventory age report and sort descending by days in fulfillment center. Anything past 181 days is already costing you the surcharge on top of storage.
• Set a September inventory ceiling per SKU. You do not want units arriving into the October storage rate that you cannot sell by December.
• Create a removal or liquidation rule at the 300 day mark. Past that point the surcharge usually exceeds what the unit will ever earn.

Section 03

The Three Newer Fees That Punish Bad Inventory Habits

These are the fees Amazon added to change your behavior, not just to recover cost. Each one is avoidable.

The low inventory level fee is the mirror image of the aged surcharge. Where aged inventory punishes holding too much for too long, this one charges you for holding too little. Per Amazon’s low inventory level fee page, the threshold sits at 35 days of historical supply, and the per unit charge scales with product size and how far below the threshold you fall. Confirm your live threshold and rate in Seller Central, because Amazon has moved this threshold before. It now calculates at the individual FNSKU level rather than the parent ASIN, so a single fast moving child variation can trigger it even when the parent looks well stocked.

The inbound placement service fee is what Amazon charges to spread your shipment across multiple fulfillment centers for you. Per Amazon’s inbound placement fee page, shipping everything to a single location using a Minimal Split runs up to roughly $0.40 per unit for standard items, and more for oversize and extra large. The way to pay zero is to use Amazon Optimized Splits, where you ship to multiple destinations and the placement fee drops to $0.

The returns processing fee runs on a dedicated rate card by size tier and shipping weight. Per Amazon’s returns processing fee page, a large standard item around 1.5 pounds carries roughly a $4.32 returns processing fee, independent of what its fulfillment fee is. Amazon applies it once your return rate for a category climbs above that category’s threshold. Apparel and shoes carry a 0% threshold, which means every return is charged, no matter how well the listing performs.

What to do this week:

• Set replenishment triggers at 45 days of cover per FNSKU, not per parent. The fee reads the child, so your reorder point has to as well.
• Switch your inbound workflow to Amazon Optimized Splits. The placement fee it saves almost always beats the extra freight of a single destination shipment.
• Pull your return rate by category and compare it to the threshold. If you are over, the fix is a listing and sizing problem, not a fee problem.

The Margin Above the Floor Is the Game

The operators who win on margin are not the ones who found a secret fee loophole. They are the ones who treat storage age, days of cover, and shipment splits as three dials they check every week, because every one of those fees is something you triggered, not something Amazon did to you.