Question: how to transfer contacts from phone to sim card on htc one?
Answer: Launch your contacts app on your HTC Android device. ... 
Press the "Menu" button and tap "Import/Export."
Tap "Export to SD Card" and tap the account containing the contacts you wish to back up to your SIM card. ... 
Install and launch the SIM Card Manager app. ... 
Press the "Menu" button and tap "Import/Export."