If you want to add more than 10 users to a Custom Group, it is recommended that you upload a CSV with the list of users. The Custom Groups CSV is a simple CSV that contains only the email addresses of the users. 

A couple of things to remember when uploading your CSV:

1. The CSV should contain only one column with the email address of users.
2. Do not enter a column header name (e.g. Email address) as it will lead to an error for that row in the CSV file.  
3. All email addresses must belong to the school domain registered with Securly. 
4. All email addresses must be unique.
5. If an email address is found to belong to another Custom Group, the user will be removed from that group and added to the group you are uploading a CSV for. 
6. All email address must be in a valid format - username@domain.com