It appears that new subaccounts have an initial limit of 100 SMS per day. To go beyond this limit, you MUST SEND❗100 SMS and then wait 24 hours before you can send again and the limit is increased to 250. Then this repeats to get to the 500 level, etc.
How do you handle DBR with these limits? If I send 100 DBR msgs (which is required to get to the 250 level), I am then restricted from responding to any clients (Or sending ANY SMS msg) for 24 hours. That really limits speed to lead!