The format for dialing is: your country's exit code + country code you are calling to + city/area code + local number.
The country code for the UK is 44.
The city code for London is 020, but you must drop the first zero when calling from overseas.
The exit code for Australia is 0011.
So, you would dial:
0011 + 44 + 20 + the eight digit number of whoever you are calling.
If you have been given a full 11 digit UK phone number, just remove the first zero and prefix with 0011 44. For example, mobile phone 07123 456789 becomes 0011 44 7123 456789.
The country code for Australia is +61. The plus sign means "insert your international access prefix here"; from London, as from most of Europe, that would be '00'. You also must drop the leading '0' from the Australian area code.
Thus, to call to Sydney from London, you would dial 00 61 2 xxxx xxxx.
0061 - no that's for calling Australia from New Zealand. The answwer is 0064
011 is the international calling code from North America. 44 is the country code for the United Kindom. 20 (or 020 when dialling within the UK) is the area code for London. So, a number like 011 44 20 3890 1234 would be a telephone number in London, UK.
The country code for Sweden is +46, no matter where you're calling from.
Country code +354 is Iceland.
Germany is country code +49.
The country code and area code of Central East Australia, Australia is 61, (0)2.
The country code and area code of South East Australia, Australia is 61, (0)3.
Colombia is country code +57.
The country code for North America (USA, Canada, etc.) is +1. The area code for Houston is 713, 281, or 832. Area code 346 will be added as a further overlay in 2014. The plus sign means "insert your international access prefix here." From Australia, that prefix is usually 0011.
pakistan
You need to know what time it is in Australia. Who ever you are calling should know that you are calling them. The international access code is 011. After the other code is 61. Dial both of those numbers and that is it.
The country calling code for Germany is 49. So 010 49 from the US.