HTC One E8 - Manual (Page 133)

How do I add an extension number to a contact number?
While creating a new contact or editing a contact's details in People, you can add an
extension number to their number so you can skip the voice prompts when calling.
1. After entering the number of the main line, do one of the following:
§ Tap P(,) to insert a pause before the phone dials the extension number. To insert
a longer pause, enter P(,) several times.
§ Tap W(;) to be prompted to confirm the extension number.
2. Enter the extension number.
Editing a contact’s information
Social network contacts cannot be edited.
1. On the People tab, press and hold the contact, and then tap Edit contact.
2. Enter the new information.
3. Tap Save.
133 People