Mobile package is a monthly plan which invoice will be issued early bill cycle.
To purchase, a customer is required to pay for the package before receiveing a SIM, and the package charge is for first bill cycle.
For next bill cycle, invoice will be issued on the date the bill cycle starts and it will display package charge of this bill cycle together with exceeding charge (exceeding call, data top up or roaming charge)
Billing cycle will start once the sim has been delivered.
Your bill cycle will start on a 30 day cycle.
To know exactly what date your bill is due, you can go to main dashboard in LINE MOBILE application and the date will be stated there for you as screenshots below.