What's the country code for calling Britain?

When making a phone call, directly add 0044 and remove the 0 in front of the phone. If the number is 07790000000, please dial: 004477900000.

2. To make a landline call, directly add 0044, and then add the area code (London is 020), but be careful to remove the 0 before the area code. For example, if the phone number is 0 13 1-5525252, you should call: 0044 13 15252.