Instead of eelying on a text Inwould.just go into your self serve account periodically, like every 5 or 7 days. Then if your data is runnning low then add on data for 15.00 for 1G. Or do the math to see if it makes more sense to move up to a higher plan.
@mdwallace97 text messages are sent out from PM 611 at 75 and 95% of your data usage. Stay safe.
This is true if you have no data add-ons on the account. If you have data add-ons, I have found no notifications are sent at all. I confirmed this in my last cycle by on-purpose using up every MB of my base data allotment.
I am not sure about if they still are sent at 75/95% of your TOTAL data allotment, but from what I've gathered from others, notifications may not be sent in that case either until all data add-ons are consumed.
With that in mind, pay regular attention to your data usage via self-serve (or 611).