What should I do if a student has created more than one account?

If the student has 2 or more different accounts, with different usernames, you can merge their duplicate accounts. This way, they will have just 1 set of login credentials and all of their assignments on one account. 

To merge a student's duplicate accounts:

1. Go to your "Manage Classes" page.
2. Click the class name for the class in which your student has created more than one account.
3. Scroll down and select the student's multiple accounts (you can only merge 2 at a time).
4. At the top of the student roster, click on the "I want to..." menu button.
5. Select "Merge selected duplicate student accounts" and click the "Apply" button next to it. 
6. Choose the username (and password) you want students to keep
   1. Note: Merging a Google and non-Google student will always preserve the Google student's email, username, and password.
   2. Note: You cannot merge two students who are both connected to Google Classroom.

This will merge your students' multiple accounts and assignments. Students will then only require one login username and password for this newly merged account.