Hi there, BookDiamond.
Thanks for reaching out to Seller Forums with your question.
I appreciate your interest in understanding what causes reserved status of your FBA inventory units. Here are a few of the most common reasons for Units being reserved:
-Units are tied to a pending order (most common reason and generally is only a few days, but, some cases, our payment and order detail verification processes may potentially extend order processing times for as long as 21 days.)
-Units are being picked, packed, or shipped for a current order
-Units are tied to a fulfillment center process. Fulfillment center processes include: dimension and weight measurement, hazardous material check, and fulfillment center transfer.
You can also view the status of reserved inventory units via Reserved Inventory Reports at:
Reports > Fulfillment > Reserved Inventory(beneath the Inventory header).
Generally, reserved status only lasts a matter of a few days, as units that are tied to pending orders sometimes await payment approval, and units being shipped between fulfillment centers require shipping time. But please do feel free to [contact Seller Support|https://sellercentral.amazon.com/hz/contact-us?encoding=UTF8&ref=su_contactus_foot_xx&urlStr=%2Fgp] if you find items are in reserved for an extended period of time and we will be more than happy to look into it.
Once again, thank you for posting here in Seller Forums. It’s a pleasure getting to assist you and I hope you’ve got an excellent Wednesday ahead of you!