User ID is a unique identifier code of Atlas VPN customers and it's used to determine the type of your subscription and provide services accordingly. Our customer care team will ask you for your User ID in order to perform any actions related to your account once requested.
You can locate your account's User ID in the Atlas VPN application settings. Here is a list of tutorials showing you how to locate the User ID on different platforms:
Please note that you should log into your account that has your active premium subscription, as otherwise, the Atlas VPN application will display a different User ID.