The Earnin app does not support two accounts using the same bank information. You can sign up for Earnin using the joint bank account once the co-owner has closed their Earnin account.
For security purposes, you won't be able to use the same bank information if your co-owner has Earnin transactions in the last 30 days. Once the cooling off period has passed, the same checking account can be used again on the app.
If you need help linking a previously used joint bank account, please contact us for assistance.