Are add-on data plans one-time?

[EdwinKCChan]

Hi,
I was wondering if the add-on data plans are one-time? e.g. I went over my data limit and needed to purchase a data add-on; when my auto-pay comes up will it just be my plan value or plan value + data add-on?

thanks

[rob79]

Once your plan renews you'll start using plan data again, but the extra add-on data will stay on your account until the next time it's needed.

EDIT: I just realized I misunderstood your question but SD08 got it covered. 

[SD08]

Only your regular plan will renew for the next cycle, not any add-ons as they are not considered part of your plan.  The add-ons will not renew, but whatever you have remaining on them will stay in your account until consumed.