Prepay account balance

You lose it. Prepaid does not refund.

Can I apply it to a new prepay line?

Hey there @WavyCrazy, we'd be happy to answer your question regarding your remaining prepaid balance. 

Be advised, as @sandblaster stated, once you've ported your number you lose your AT&T prepaid balance, and you're unable to generate this balance to another prepaid line or account. 

We are sorry for this inconvenience, and we hope we were able to answer your questions and concerns. 

Thanks for contacting the AT&T Community Forums for help.

Lynn, AT&T Community Specialist 

Lynn was saying no, in at&t speak. 

Prepaid balance is not refundable or transferable. It stays with the number. If you do not wish to stay for 360 days, don't buy the $300 plan. AT&T has a $30 plan with 5 GB that's good for 30 days if you want to try out the service with a throw away number and plan

Bad year this to be WavyCrazy.

Thanks everyone for the prompt responses