If you already own a perpetual license and need to retrieve your serial number, you can find it through the following official channels: Adobe Account : Log in to the Adobe Account Management
portal using the email address used for the original purchase. Registered serial numbers are listed under Plans and products Order Confirmation Adobe Acrobat Xi Pro 11.0.12 Serial Number
Adobe Acrobat XI Pro is a legacy product that reached its End of Support on October 15, 2017 If you already own a perpetual license and
: If you purchased a physical copy, the serial number is typically located on the disc sleeve or the product box. Important Considerations Invalid Serial Number for Acrobat Xi Pro - Adobe Community Product Box
: Check the email account associated with your purchase for a confirmation message from Adobe or the authorized retailer. Product Box
. Adobe no longer sells or provides serial numbers for this version, and its activation servers have largely been retired.