UnionID is a user’s identifier within the Tencent environment, including WeChat, which remains the same and unique for each user.
Businesses in China commonly have a number of WeChat touchpoints: Official Accounts, Mini Programs etc. A user connecting to these touchpoints will get a different OpenID for each touchpoint. The one identifier given by Tencent which allows to uniquely identify each user is called UnionID. The UnionID is unique each WeChat Open Platform account, including Mini Programs, all mobile applications and web applications, and all OpenIDs.
In short, the same user has the same UnionID for different applications under the same WeChat Open Platform.
A WeChat user as seen in the Splio backend. The UnionID allows the user to be uniquely identified for all their visits to an H5 site, Mini Pogram, and Official Account.
How to apply for UnionID
To apply for a UnionID follow these steps:
1. Register an Open Platform account
Go to https://open.weixin.qq.com and register your account. There are no specific requirements for registration, you only need to verify an email address.
2. Complete Developer qualification
Log in to the Open Platform, go to Account Center and select Developer Qualification.
A verification fee of CNY 300 (in Mainland China) or USD 99 (outside Mainland China) is required.
3. Bind your WeChat touchpoints to the Open Platform
To bind your WeChat touchpoints (Official Accounts, Mini Programs, etc.) to the Open Platform, do the following:
- go to Admin Center
- select “Official Account” or “Mini Program”
- Use the “Bind an Official Account / Mini Program” option.
Limitations of Open Platform
A single Open Platform can bind up to 50 Official Accounts and 50 Mini Programs for the same entity and of 5 Official Accounts and 5 Mini Programs if the entities are different.