I am currently on NBN FTTC SL Bundle Fast for $69.99 p/month. I would like to know can i upgrade to the NBN 100 for $89.99 for a few months then change back to my original plan of $69.99, or once i change my plan to $89.99 do i have to stick with that plan?
Welcome to the community!
We're glad to know that you're considering to upgrade your NBN Plan. Yes, you may process the change of plan anytime you want we'd like to set your expectation that any unused portion of your current billing will be used towards the new plan.
We did an article that you may find helpful, see this link, Changing NBN Plans through My Account.
Should you need further assistance, feel free to search community for help or chat with us at https://www.tpg.com.au/support/contact/ and we'd be glad to assist you.