HTC One M8 User Manual page 173

2. Enter the phone number or first few letters of the contact's name to
see the top matching contact.
3. If there are a number of matches found (for example, 8 matches),
tap the number to see all the matches.
4. Tap the contact you want to call.
If you selected a contact whose phone number has a leading zero,
HTC One will automatically prepend it with your home country
code when dialing. If there's already a plus (+) sign and country
code before the phone number, HTC One will just dial as is.
HTC One dials as is and does not prepend your home country
code when you call phone numbers that are not stored in
HTC One. When manually entering a phone number to call, you
need to enter a plus (+) sign and country code before the number.
Editing a country's international call settings
1. Go to Settings, and then tap Call.
2. Tap Assisted Dialing > Reference Country.
3. Under Reference Country, select the country whose settings you
want to edit.
4. Tap > Edit.
5. Edit the Country Code, IDD Prefix (International Direct Dial), NDD
Prefix (National Direct Dial), Area/City Code and National Number
Length (length of phone number).
6. Tap Save.
Video chat and phone calls 173