If you change SIM card while keeping the same operator and plan (for example if you renew the card, change the phone or SIM format), the identification number (IMSI) of your card will change but you probably want to keep the usage history associated with the old card.
3G Watchdog Pro offers a function (3GW main screen > Menu > Migrate SIM card) to migrate the history from the old card to the new one.
The procedure assumes that the new SIM card is installed in the phone and active. It is recommended to do the migration ASAP after the installation of the new card, as any data associated with the new card will be overwritten with data from the old card, so if you proceed early you won’t lose any information.
If 3GW finds more than one potential “old” cards to migrate you will be requested to select one. The candidate SIM cards are listed with their ID (IMSI number) and usage for the current plan period to help you pick the correct one.
3GW does automatically backup your data before proceeding to the migration. In case of problems you can restore this backup.