Yes, you can change your base plan anytime in Prepaid Self Serve
or by dialling *611 on your phone (it's a free call!).
If you're changing your base plan while there is an active base plan already on the account, just remember that the change is applied immediately and you won't be refunded the days remaining in your current base plan. If you choose to do this, be sure to have sufficient service credits on your account to cover the cost of your newly selected base plan, otherwise your service will be suspended.
If you're changing your base plan in Self Serve while your service is suspended due to an expired rate plan, we suggest you change the base plan first, and then top up as the second step.