Please enter all phone numbers in E.164 format. No leading “0″s, no international trunk code, just a “+” followed by the country code, followed by the rest of the number.
The country code in the United States and Canada is 1, so the number would be entered as: +1 555-555-5555.
In the UK and many other countries internationally, local dialing requires the addition of a 0 in front of the subscriber number. However, to use E.164 formatting, this 0 must be removed. A number such as 020 7183 8750 in the UK would be formatted as +44 20 7183 8750.