Instructions for calling from the UK to international locations requires special calling codes that allow you to connect to countries outside of the United Kingdom.
Calling out to Vietnam
Here are the instructions on how to call the country of Canada from the United Kingdom.
To call Vietnam, dial 0084 and then enter the phone number of the person or location you’re trying to reach. If the phone number is displayed with a leading +84 omit the 84 and replace it with the UK international dialing code of 00. For example:
Phone Number in Vietnam
Dialed from the United Kingdom
+84 xxxx xxxxxx
00 xxxx xxxxxx
00 2057 346368
How to call the UK from Vietnam
To call a landline or mobile phone in the United Kingdon from Vietnam, dial 00 44, then dial the UK phone number, minus the leading zero. For example: