Can a user send beyond their assigned SMS credit?

No, the user won’t able to send out more than their credit limit. If the AutoResetQuota set to “N”.

Example:

The Administrator has set 100 SMS credits to User A.  When User A had sent out 100 SMS credits they will not be able to send any more SMS unless the AutoResetQuota set to “Y”.

If you have hit your SMS limit, please contact your company administrator.