How to make International Phone Calls International Country Codes & IDD prefix

To call to a BTTB phone, dial Like this:
IDD Prefix of the country FROM which you are calling - Country Code of Bangladesh (880) - Area Code without the leading zero - Phone number.
DO NOT press the leading zero of the area code. For example the area code of Dhaka is 02. But when you call from overseas to Dhaka, do not press the zero (0), just press 2. So, if you want to call 8151234 at Dhaka, press: (IDD prefix)88028151234

List of the IDD prefix for most of the countries of the world is given in a table below. Press the IDD prefix of the country FROM which you are calling. If you are using a Prepaid Telephone Card or VOIP, you may not need to dial an IDD prefix or you may have to dial a different IDD prefix. Please read the instruction of the Telephone Card or VOIP provider that you are using.
List of the Country Code for most of the countries of the world is given in a table below. Use the Country Code for the country TO which you are calling.
To call to a Mobile phone in Bangladesh, dial Like this:
IDD Prefix of the country FROM which you are calling - Country Code of Bangladesh (880) - Mobile phone number without the leading zero (1721251234).
DO NOT press the leading zero of the mobile phone number.
If you want to call 01721251234 at Grameen Phone, press: (IDD prefix)8801721251234
If you want to call 01552512345 at Tele Talk, press: (IDD prefix)8801552512345
To make an international call from Bangladesh:
To call to a Fixed line phone or Home phone in another country dial like this:
IDD Prefix of Bangladesh - Country Code of the country TO which you are calling - Area Code without the leading zero - Phone number

The IDD Prefix for the countries included in the EISD (Economy International Subscribers' Dialing) list is: 012
If you are calling to Australia, in the Sydney area and the phone number is 92661234 , then you should dial: 012-61-2-92661234 [IDD Prefix for EISD country is: 012 - Country Code of Australia is: 61 - Area Code of Sydney is: 02 - Phone number is: 92661234]. The City Code of Sydney is: 02. But you should NOT press the leading zero (0) of the city code.

If you are calling to a country that is NOT in the EISD list, you should use the normal IDD prefix of Bangladesh, which is: 00 (and in this case do not press 012).
For the EISD list, please visit the BTTB website: http://www.bttb.net/    OR    http://www.bttb.gov.bd/home/main/rates/EISDrate.htm
To call to a Mobile phone or Cell Phone dial like this:
IDD Prefix of the country FROM which you are calling - Country Code of the country TO which you are calling - Mobile or cell phone number without the leading zero.
To make an international call from any country of the world:
Follow the same system mentioned above.

To call to a Land Phone or Home Phone dial like this:
IDD Prefix of the country FROM which you are calling - Country Code of the country TO which you are calling - Area Code without the leading zero - Phone number
To call to a Mobile Phone or Cell Phone dial like this:
IDD Prefix of the country FROM which you are calling - Country Code of the country TO which you are calling - Mobile or Cell Phone number without the leading zero.
You just need to know the IDD Prefix of the country FROM which you are calling and the Country Code of the Destination country TO which you are calling.