UnionID Mechanism Description | Weixin public doc

# UnionID Mechanism Description

If the developer has multiple mobile applications, web applications, and official accounts (including Mini Games), the uniqueness of the user can be distinguished by the unionid. As long as it is a mobile application, web application, and official account under the same Weixin Open Platform account (including Mini Game), the user's unionid is unique. In other words, the same user has the same unionid for different applications under the same Weixin Open Platform.

# Ways to Get UnionID

Mini Game that has a developer account bound to it can obtain the UnionID through the following three ways.

Call the interface wx.getUserInfo to obtain the UnionID from the decrypted data. Note that this interface requires user authorization. Developers are required to properly handle the situation after the user rejecting the authorization.
If there is an official account for the same entity under the developer's account, and the user has followed the official account. The developer can obtain the user's UnionID directly via wx.login without the need for the user to authorize again.
If there is an official account or mobile application for the same entity under the developer's account,, and the user has authorized to login to the official account or mobile application. The developer can also obtain the user's UnionID directly via wx.login without the need for the user to authorize again.

# Process of Weixin Open Platform Binding Mini Game

Prerequisite: Weixin Open Platform account must have completed developer qualification.

Developer qualification certification process:

Binding process: