FBA prep and box checker
Amazon accepts FBA boxes up to 36 inches on the longest side, 25 inches on the other two sides and 50 lb, unless the box holds a single oversize or heavy item. Every box needs its own FBA box ID label, and units need the prep their type calls for: poly bags at least 1.5 mil thick with a suffocation warning when the opening is 5 inches or wider, “Sold as set” labels on sets, and expiration dates on every unit and on the outer box.
Example values; replace them with your box.
How the units are packed
1rule fails
Fix it before you create the shipment in Seller Central.
This 28 × 26 × 16 in, 44 lb box of 24 units fails on box size.
- Box size (fails)
- Box weight (passes)
- Box ID label (to do)
- Unit barcodes (to do)
- Bag thickness (passes)
- Suffocation warning (to do)
- Expiration dates (to do)
Checklist for this box
Rules checked on Amazon’s site on 2026-10-30; Amazon updates them, so confirm in Seller Central before shipping.
Passes: checked against your numbersFails: change the box before it shipsTo do: applies to this box, check it yourself
Fails
Box size
28 × 26 × 16 in: width 26 in is over 25 in.
Repack into boxes no larger than 36 in on the longest side and 25 in on the other two.
Passes
To do
FBA box ID label
Every box, in every shipment.
Print a unique FBA box ID label for each box (never photocopy one) and put it on a flat face with the carrier label, not over a seam, edge or corner.
To do
Unit barcodes
All 24 units.
Each unit needs a scannable barcode on a flat face, at least 0.25 in from the edges and not on a curve or corner, with other barcodes covered. Since March 31, 2026, resellers must use Amazon barcodes (FNSKU labels); brand owners in Brand Registry can use manufacturer barcodes.
Passes
Poly bag thickness
1.5 mil, at least 1.5 mil.
Seal the bag fully, keep it within 3 in of the product, and make sure the barcode scans through it or sits on the outside.
To do
Suffocation warning
A 9 in opening is 5 in or wider.
Print Amazon’s suffocation warning on the bag or stick it on as a label, in type sized for the bag.
To do
Expiration dates
Dated on each unit and on the box.
Show the date on every unit and on the outer box in 36-point type or larger, outside any bag or wrap, and pack one expiration date per product per box. MM-YYYY is accepted on both of Amazon’s pages; for full dates its pages differ on day and month order, so match what Seller Central shows you.
How Amazon’s box rules work
Amazon’s fulfillment centers set two kinds of rules. Box rules cover the shipping carton: its size, its weight, and the FBA box ID label that tells receiving what is inside. Prep rules cover each unit: the barcode, and the bag, wrap, box or label its product type needs so it can be stored and shipped on its own.
The size limit is not a cube. Since June 20, 2025, a U.S. FBA box can be 36 inches on its longest side but only 25 inches on the other two, so a 28 × 26 × 16 inch box fails on its width while a 36 × 20 × 20 inch box passes. The checker sorts your three sides and applies 36 inches to the longest and 25 to the others, whichever way you entered them.
Longest side ≤ 36 in, other two sides ≤ 25 in, weight ≤ 50 lb
Boxes that miss a rule can be refused at the dock, sent back or prepped by Amazon for a fee, and repeated problems can block future shipments. Weigh and measure every box: Amazon requires accurate box weights and dimensions for every shipment.
Before you settle on a carton, check how carriers will bill it with the dimensional weight calculator, and whether UPS, FedEx and USPS accept it with the package size limits checker. If you’d rather not prep and label units yourself, see how our FBA prep services work, or compare FBA, FBM and a 3PL side by side.
The limits this checker uses
| Rule | Limit |
|---|---|
| Box size, more than one item | 36 in on the longest side, 25 in on the other two |
| Box size, one oversize item | May exceed 36 × 25 × 25 in only if the item is longer than 36 in |
| Box weight | 50 lb, unless the box holds one item over 50 lb |
| Heavy boxes | Over 50 lb: “Team lift” labels on top and four sides. One item over 100 lb: “Mechanical lift” labels |
| Jewelry and watches | 40 lb per box |
| Case packs | Up to 150 units, same SKU and quantity in every box |
| Poly bags | At least 1.5 mil; suffocation warning on openings of 5 in or more |
| Unit barcode | Flat surface, 0.25 in from the edges, labels 1 × 2 in to 2 × 3 in |
| Expiration dates | On each unit and the outer box, 36-point type or larger |
| Non-hazmat liquids | No extra prep at 4.2 oz (125 mL) or less |
Common questions
What is the maximum box size for Amazon FBA?
A box with more than one item can be up to 36 inches long and 25 inches on each of the other two sides, and weigh up to 50 lb. Amazon raised the length limit from 25 to 36 inches for U.S. FBA shipments on June 20, 2025. A box can exceed these sizes only if it holds a single item longer than 36 inches, and then it shouldn’t be much bigger than the item.
Can an FBA box weigh more than 50 lb?
Only if it holds one item that weighs more than 50 lb. That box needs “Team lift” or “Heavy package” labels on the top and all four sides. A single item over 100 lb needs “Mechanical lift” labels on the top and sides. Boxes of jewelry or watches are limited to 40 lb.
When does a poly bag need a suffocation warning?
When the bag’s opening is 5 inches or wider, measured flat. The warning can be printed on the bag or stuck on as a label. Amazon also requires bags to be at least 1.5 mil thick, fully sealed, and no more than 3 inches bigger than the product, with the barcode readable through the bag or placed on the outside.
How do I label expiration-dated products for FBA?
Show the expiration date on every unit and on the outer box in 36-point type or larger, outside any bag or wrap. Pack only one expiration date per product in each box. Amazon’s help pages accept MM-YYYY; for full dates its packaging page and its expiration-date page list the day and month in different orders, so follow what Seller Central shows when you create the shipment.
Where should the FNSKU label go?
On a flat surface of each unit, at least 0.25 inch from the edges and not around a curve or corner, with any other barcodes covered. Since March 31, 2026, resellers must use Amazon barcodes (FNSKU labels) even if the product has a manufacturer barcode; brand owners in Brand Registry can keep using manufacturer barcodes.
Can Fulfillment Hub USA prep my FBA shipments?
Yes. FBA and FBM prep is one of Fulfillment Hub USA’s services, alongside storage, kitting and freight support, from five U.S. warehouses. Onboarding typically takes 3 to 5 business days.
Sources
- Amazon Seller Central: Shipping and routing requirements (box size, weight and lift labels)
- Amazon Seller Central: Product packaging requirements (sets, case packs, expiration dates)
- Amazon Seller Central: Bagging requirements
- Amazon Seller Central: Expiration dates on FBA products
- Amazon Seller Central: Use Amazon barcodes for FBA (label placement)
- Amazon Seller Central: FBA barcode requirements (March 31, 2026 change)
- Amazon Seller Central: Shipping label requirements (FBA box ID labels)
- Amazon Seller Central: Fragile products
- Amazon Seller Central: Liquid products
- Amazon Seller Central: Packaging sharp units
- Amazon Seller Forums, Amazon news: maximum FBA box length rises to 36 inches (June 20, 2025)
Checked 2026-10-30. Rules change; confirm with the carrier or agency before you rely on a number.
More shipping and inventory tools
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