To change your billing period, you need to be on the most recent eSIM from World Mobile. First, log into your account at my.worldmobile.io. Then, access the line you wish to change under 'Plans' then 'Manage'. At the bottom of your line, you will find the option to change your billing period to the timeline of your choice. If you do not see the option to change your billing period on your line, you will need to request the latest eSIM by submitting a ticket.