Amazon Marketplace Web Service (MWS) will no longer be available after March 31, 2024. All MWS developers must migrate to Selling Partner API (SP-API) to avoid service disruptions. Refer to the Migration Hub for more information.
When you submit inventory feeds (using the Feeds API section) to update inventory levels for items that you sell on Amazon's website, never leave the fulfillment-center-id null. For self-fulfilled inventory, enter DEFAULT in this column. For Fulfillment by Amazon inventory, enter either AMAZON_NA, AMAZON_EU, AMAZON_JP, or AMAZON_IN depending on your marketplace. This helps ensure that each item is fulfilled as you expect it to be.
For more information, see Listings Reports.