A concise reference for used booksellers. What Amazon charges to warehouse your inventory, when the surcharges start, and how they compound over time.
Amazon charges a monthly fee for every cubic foot your inventory occupies in their fulfillment centers. Rates spike during Q4 (Oct-Dec) when warehouse space is at a premium.
| Size Tier | Jan - Sep | Oct - Dec |
|---|---|---|
| Standard-size | $0.78 / cu ft | $2.40 / cu ft |
| Oversize | $0.56 / cu ft | $1.40 / cu ft |
Amazon takes a snapshot of your inventory on the 15th of each month. Every unit in the warehouse at that moment gets billed based on its cubic footage. Cubic feet = (L × W × H) ÷ 1,728 using the unit's dimensions in inches.
For most books, base storage is cheap -a few cents per unit per month. The real cost comes from the aged inventory surcharge below.
This is the fee that catches sellers off guard. It kicks in at 181 days (roughly 6 months) and escalates in 30-day steps. It's charged on top of your base monthly storage.
| Inventory Age | Surcharge / cu ft | Per-Unit Minimum | Severity |
|---|---|---|---|
| 0 - 180 days | - | - | No surcharge |
| 181 - 210 days | $0.50 | - | Low |
| 211 - 240 days | $1.00 | - | Moderate |
| 241 - 270 days | $1.50 | - | Moderate |
| 271 - 300 days | $5.45 | - | Elevated |
| 301 - 330 days | $5.70 | - | Elevated |
| 331 - 365 days | $5.90 | - | High |
| 366 - 455 days (12-15 mo) | $6.90 | $0.30 / unit | Critical |
| 456+ days (15+ mo) | $7.90 | $0.35 / unit | Critical |
Books are small, so the per-cubic-foot charges often work out to pennies. But at 12 months, the $0.30/unit minimum kicks in -you pay $0.30 regardless of size. At 15 months, it jumps to $0.35/unit. For a $5 commodity book, that's 6-7% of your sale price eaten by storage every single month.
The per-unit minimums increased this year. Previously $0.15/unit at 12 months and $0.20/unit at 15+ months. They've now doubled to $0.30 and $0.35 respectively. The per-cubic-foot rates stayed the same.
Here's what the fee timeline looks like for a single book from the day it arrives at an FBA warehouse:
Here's what storage actually costs across four common book formats. Off-peak figures use Jan-Sep base rates ($0.78/cu ft). The Q4 section at the bottom of each card shows what happens during Oct-Dec when base storage triples to $2.40/cu ft.
For mass market and trade paperbacks, size doesn't matter past 12 months -the $0.30 per-unit minimum is the floor and it's the same for every book. Only large hardcovers and textbooks pay more than the minimum because their cubic footage exceeds the breakeven point (~0.043 cu ft).
At its core, the AIS decision is simple: will this book earn more than it costs to hold?
| Situation | Action |
|---|---|
| Approaching 6 months, steady sales velocity | Hold. Base storage is negligible. |
| Approaching 6 months, zero or near-zero sales | Reprice now. You have 3 months before fees ramp. |
| At 9-10 months, no sales | Last call to reprice aggressively or create a removal order. |
| Past 12 months, book is worth < $10 | Remove. The $0.30/mo bleed erodes your margin fast on low-value books. |
| Past 12 months, book is worth $20+ ($10+ net) | Hold if there's demand. $0.30/mo is noise on a $10+ net payout. |
| Past 15 months | Serious scrutiny. $0.35/mo = $4.20/yr per unit minimum. Only hold high-value studs. |
Total AIS paid if a standard book (trade paperback) sits unsold from day one. Cumulative, not monthly.
| Age | AIS This Month | Cumulative AIS | + Base Storage | Total Cost to Hold |
|---|---|---|---|---|
| 6 months | $0.00 | $0.00 | $0.09 | $0.09 |
| 9 months | $0.03 | $0.06 | $0.14 | $0.20 |
| 12 months | $0.30 | $0.40 | $0.19 | $0.59 |
| 15 months | $0.35 | $1.30 | $0.23 | $1.53 |
| 18 months | $0.35 | $2.35 | $0.28 | $2.63 |
| 24 months | $0.35 | $4.45 | $0.37 | $4.82 |
A trade paperback sitting unsold for 2 full years costs roughly $4.82 in storage and AIS. If you paid $1 for that book and it sells for $12 (netting ~$3.40 after fees), you've already lost money - the $4.82 in storage plus your $1 cost of goods ($5.82 total) exceeds your $3.40 payout. The storage ate your profit and then some.