Acrobits Softphone for Android supports multiple SIP accounts with simultaneous registrations. But there may be times that you need to disable or delete a SIP Account. Just do the following.
1. Tap on settings, then SIP Accounts, then the gear symbol nest to the SIP Account.
2. This should take you to the main settings screen for the SIP Account.
3. Press menu and you should see the option to disable or delete the account.