In case a parent locks their account, do the following:

1. Lookup Student Record
2. Click Access Accounts
3. In the section for Parent Access Accounts the username will have Locked Out in parentheses
4. Click Modify for this account
5. The Edit Parent page will show with a link to Unlock account at the top
6. Click the Unlock account link

Keep in mind, the parent may need to have their password reset. You can reset their password and provide in a secure/verified manner or walk them through the Forgot Password method. 

Also, parent portal account has to be link to an Active Student.  For example, after a student is transferred out, the partent won't be able to login even if their Parent Portal account isn't locked.