To add an account click on Add a subaccount
Note: to set default settings to all new accounts head over to Settings > Default Settings.
Enter the name of the account and choose the Parent (the account you want this subaccount to depend on). When choosing a parent, the number of dashes will help you understand the hierarchy of accounts. However, you can always search by simply typing the name of the account.
You can also enter a Monthly Volume Limit if you want to restrict how many SMS the account sends per month. If you leave this box empty it means they can send as much as their balance allows them to.
TIP: When giving an account a new name, try to make it easier for YOU to remember and search for, especially if you'll be manning many subaccounts.
Billing/ Payment Details
Credit management lets you determine whether this sub account will pre-purchase credits (in other words, if the credits will be allocated from the parent account, so it will be sending from a credit balance) or if it will be able to send unlimited SMS (in other words, if it will deduct credits from the parent as it sends).