Fulfillment Latency is an Amazon setting to mark an item as requiring additional lead time to ship. If it is set on a specific product, it will be updated with the regular inventory update feed. For example, when set to 5 days, it will appear on Amazon with a message like: "Processing takes an additional 4 to 5 days for orders from this seller."
Setting Fulfillment Latency
The next time an Amazon inventory update is sent, the value will be updated automatically, since it gets included in the inventory feed.
Setting Fulfillment Latency Defaults
To control the fulfillment latency on a company level for all products, enter a lead time to ship in the Amazon General Settings page. Enable the Use Default on the product level (can be enabled with a bulk update with the column header FulfillmentLatencyForAmazonUseDefault in BulkUpdateProducts).
Override Fulfillment Latency
You can also temporarily override a lead time to ship set at a product level. For example, if you will be away on vacation, instead of setting your account to Vacation Mode, you can use the global setting to temporarily extend the lead time to ship for an extended period of time this will allow customers to continue purchasing your products while delaying the time to ship until after you come back from the vacation. To set this, open the Amazon General Settings under Company Settings. Change the default fulfillment latency to the amount of time you want to allow yourself before shipping an item. Now enable the Global Fulfillment Latency option. Now, the system will set the lead time to ship for all products based on the longer lead time to ship period. For example, if the default has been set to 5 days and the product to 2 days , the latency wil be set to 5 days. If, however, the product has been set to 8 days, the lead time to ship will remain at 8 days even though the global setting has been enabled.
Note: There is a similar setting for eBay called MaxDispatchTime, but it is different and limited to values 1, 2, 3, 4, 5, 10, 15 and 20 days.