Amazon has very specific requirements for shipping. The pallet has to be 40 inches by 48 inches (100cm x 120cm) and not more than 72 inches or 182.5 cm high for a single pallet (together with the pallet itself). And for double-stacked pallets, the maximum height is 100 inches or 254cm.
If you're shipping a full container (FCL) to an Amazon warehouse, you have a few options for filling (stuffing) the container to comply with FBA receiving requirements.
1. Ask the forwarder to palletize them before arriving at the Amazon warehouse
You can ship your goods in boxes and pay your freight forwarder to unload and transfer them to Amazon-accepted pallets for last-mile delivery.
If you choose this option, make sure your boxes are labeled according to Amazon's specifications.
2. Have the supplier load the container with pallets
Your supplier can load your container with palletized goods. If everything is labeled and palletized correctly, it can be sent straight to the Amazon warehouse.
This option only works if you have a single FBA delivery location.
3. Floor load the container with boxes
Although Amazon prefers shipments delivered on pallets, it will accept containers stacked with boxes (for an added processing fee).
Just know that pallets are often prioritized over floor-loaded containers, so it might take longer to schedule a delivery appointment. This means you might be charged for storage while your provider waits for a delivery slot.
Amazon has specific labeling and packaging requirements for floor-loaded containers.
Read this article for an overview of when to palletize your shipment for Amazon FBA.