How to write a valid mobile phone number in international format?

National dialing codes when calling internationally

In several countries, you may need to add a zero (0) when dialing a number inside the same country.

To dial a number in the United Kingdom, dial the internal area code (01296). The number would look like this: 01296 999999.

To call the same number from outside of the UK, it is not necessary to add the zero (0) before the area code. In this example, the number would be just 1296 999999. Also you need to add the country code, and the number will look like 44 1296 999999.

If you want to dial the same number from France, for instance, you would need to dial double zero (00) first. Putting it all together: 00 44 1296 999999.

How to dial an international number

In the United States, you need to dial 011 before the country code; however, in Europe, you dial 00. Here are the options:

• 011 44 9999 999999
• 00 44 9999 999999
• +44 9999 999999

List of International Calling Codes