How to backup contacts, calendar and tasks from Nokia Lumia 730 Dual SIM
We used PhoneCopy.com service for this guideline. Using it, your can backup your contacts from your Nokia Lumia 730 Dual SIM easily. The whole backup, including the settings, can be done in several minutes.
Download the PhoneCopy application from windowsphone.com. If you do not have a PhoneCopy account yet, press "Register new account" and create it by filling in "Registration" and then press "Sign up".
If you already have a PhoneCopy account, fill in your username and password. To export your contacts, press "Export to PhoneCopy.com". If you want to upload your merged contacts back to the same Windows Phone 8.1, it is necessary to delete all contacts there first.
Once everything is done, check your data on the web. Login to PhoneCopy webpage and you will see brief review of all data transferred from your device. With another mouse click, you can review the change of each particular item.
Some additional tips:
On your online account, you will see full history of your contacts, as well as the data that you've deleted in between the synchronizations. You can find them in an archive from where you can restore them. And if this is still not enough of a backup for you, you can download a CSV file, that you can store in your computer.