What FBA Storage Fees Really Cost Over a Year

A single cubic foot of standard-size inventory left in Amazon’s fulfillment network for a full calendar year costs $15.03 in monthly storage alone, before any surcharge. That figure comes from Amazon’s published schedule: $0.87 per cubic foot per month from January through September, and $2.40 per cubic foot per month from October through December. Nine months at $0.87 is $7.83. Three months at $2.40 is $7.20. Sellers who think of storage as a rounding error are usually reasoning from the off-peak rate and forgetting that the fourth quarter costs nearly as much as the other nine months combined.

The published rates

According to Amazon Seller Central’s monthly inventory storage fee documentation, standard-size inventory is charged per cubic foot per month at two rates depending on the season. January through September is the lower rate. October through December is the peak rate, reflecting the cost of warehouse capacity during the holiday period.

Storage is calculated on average daily volume across the month, not on a snapshot. Removing units on the 28th does not avoid the charge for the days they were there. Oversize inventory is charged on a different schedule.

Fee schedules change. These are the rates as published for the 2026 schedule, and any seller building a model should verify against Amazon’s current documentation rather than a figure copied from an article.

The aged inventory surcharge is where the real money is

Monthly storage is predictable and modest. The surcharge for inventory that sits too long is neither.

Per Amazon Seller Central’s aged inventory surcharge documentation, the bands effective January 16, 2026 run as follows: $0.50 per cubic foot at 181 to 210 days, $1.00 at 211 to 240 days, $1.50 at 241 to 270 days, then a sharp step to $5.45 at 271 to 300 days, $5.70 at 301 to 330 days, and $5.90 at 331 to 365 days. Beyond a year it is $6.90 per cubic foot or $0.30 per unit at 366 to 455 days, and $7.90 per cubic foot or $0.35 per unit at 456 days and over, charged at whichever is greater. Clothing, shoes, bags, jewelry and watches are excluded.

The step between 270 and 271 days is the number worth memorizing. The surcharge goes from $1.50 to $5.45 per cubic foot, a jump of more than three and a half times, for a single additional day of age. That is not a gradual penalty. It is a cliff, and it is placed deliberately at roughly nine months.

A worked example

Take a seller with 40 cubic feet of a slow-moving SKU that arrived in the network on February 1 and is still there at year end.

Monthly storage first. February through September is eight months at $0.87 per cubic foot, so 40 cubic feet costs $27.84 per month, or $222.72 across those eight months. October through December is three months at $2.40, so $96.00 per month, or $288.00. Monthly storage for the eleven months comes to $510.72.

Now the surcharge. Inventory that arrived February 1 crosses 181 days around the start of August, 211 days in early September, 241 days in early October and 271 days in early November.

August falls in the $0.50 band, costing $20.00 for 40 cubic feet. September falls in the $1.00 band, costing $40.00. October falls in the $1.50 band, costing $60.00. November and December fall in the $5.45 band, costing $218.00 per month, or $436.00 for the two months. Surcharge total is $556.00.

Combined carrying cost for that one SKU across eleven months is $1,066.72, and more than half of it lands in the final two months. A seller who cleared that inventory by the end of October would have paid roughly $630 instead.

The exact figures for any specific business depend on average daily volume, size tier and the age profile of the units, so this example illustrates the shape of the cost rather than predicting a particular outcome.

Why this shows up as a surprise so often

Three reasons, and all three are accounting problems rather than operations problems.

Storage is deducted inside the settlement. It never arrives as an invoice. A seller who records the net marketplace deposit as revenue has no storage expense line at all, which means the cost is invisible even while it is being paid.

Inventory is rarely tracked by age. Most sellers know how many units they have. Far fewer know how long those specific units have been sitting. Without an age profile there is no way to see a surcharge band approaching.

The peak rate coincides with peak distraction. The fourth quarter is when the rate triples and when nobody has spare attention for inventory review.

How the cost should appear in the books

Storage and the aged inventory surcharge are operating expenses. They should appear as their own line at full value, extracted from the settlement rather than buried in it.

This requires decomposing each payout into components. A marketplace deposit arrives net of referral fees, fulfillment fees, storage, advertising, refunds, reimbursements and reserve movements. Splitting that apart by hand from the settlement report works below a few hundred orders a month and stops being realistic above it, which is why platforms built for multi-marketplace sellers, ConnectBooks among them, decompose settlements and carry inventory alongside cost of goods sold.

The second requirement is an age profile. If inventory is tracked with a received date, the surcharge becomes forecastable months ahead, which converts it from a surprise into a decision.

What to do with the number

Three actions follow from understanding the schedule.

Review age bands in the third quarter, not the fourth. By the time peak rates apply, the units approaching 271 days are already committed. The decision window is August and September.

Price clearance against carrying cost, not against original margin. A unit heading into the $5.45 band has a known future cost. Compare a markdown today against that cost plus the peak storage rate, rather than against what you hoped to sell it for.

Include carrying cost in reorder decisions. A SKU with a twelve-month sell-through rate carries a materially different true cost than one that turns in sixty days, and a margin figure that ignores storage will rank them incorrectly.

Fee schedules are revised regularly, so any seller modeling this should date their assumptions and re-check the published rates each year. Amazon’s Seller Central documentation is the authoritative source, and a seller with meaningful aged inventory should discuss the write-down and valuation implications with their accountant.