How do you use a UK mobile in the US?

Answer 1

If someone else is calling you, they should dial the UK mobile number exactly the same way they do when you are at home in the UK. The mobile network will automatically re-route the call, and any costs for the international part of the call will be borne by you, the mobile user.

If you are calling out, the most reliable way is to enter the number in full international format, starting with the country code, whether it's a UK, US, or other-country number. The country code for the UK is +44; the US is +1. Be sure to include the plus symbol when entering numbers in international format.

You may also be able to dial US numbers with just the area code and number while you are roaming in the US, but if that method fails, use the full international format as described above.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)