On the Shopee platform, the sub-account username is composed of the main account username and the sub-account number. Specifically, the sub-account username format is "main account username_sub-account number", where the main account username is the username used when registering the main account, and the sub-account number is the number automatically generated by the Shopee system.

For example, if the main account username is "shopee_user" and a sub-account numbered "001" is created, the sub-account username is "shopee_user_001".

It should be noted that the sub-account username cannot be changed, but the sub-account nickname and password can be changed.