Excess Data Compared Chart (valid June 1, 2015) For a 1GB Data Block here are the following Costs, opt-in conditions and duration by company: Amaysim: Cost = $9.90; One time opt-in (charged monthly until cancelled); Last for 30 days Optus: Cost = $10; Automatic opt-in; Data expires at end of billing cycle Telstra: Cost = $10; One time opt-in (then automatic); Data expires at end of billing cycle Virgin Mobile: Cost = $10; One time opt-in (charged monthly until cancelled); Unused data rolls over 1 billing cycle only Vodafone: Cost = $10; Automatic opt-in; Data expires at end of billing cycle The Alternative per Megabyte charge by company is: Amaysim: 7.2c Optus: N/A Telstra: 3c Virgin Mobile: 5.2c Vodafone: N/A Notes: Opt-in conditions differ. Make sure you check the specific conditions for your account. For Amaysim and Virgin, once you add a 1 GB block to your account you will be charged each month moving forward, even if you don’t use any of it. For Optus and Vodafone, the data blocks automatically apply once your included allowance is exhausted