What dialing code do you use to call England from California?

The telephone country code for the United States (plus Canada and certain Caribbean-ish islands) is +1. You then need the area code (always 3 digits) and the subscriber number (always 7 digits).

Calling on a mobile phone, just enter the number in international format, beginning with the plus symbol; for example, +1 212 555 0123.

Calling on a landline phone, substitute the international access prefix 00 for the plus symbol.