One of our clients has run into this issue several times. She hits her SMS sending limit while a workflow is in progress, which causes inconsistent results. Some contacts receive the SMS step as expected, while others are marked “unsuccessful” and still continue through the remaining workflow steps.
We would like the system to detect when the account has reached its SMS sending limit and automatically pause or stop contacts from progressing until sending is available again. Right now, contacts can move forward even if the SMS step fails, which means they miss part of the messaging sequence the workflow is intended to deliver.