The country code for calling the United States from abroad is 001. The country code 011 is used when making an international call from within the United States. So in summary:
- 001 is the country code used when calling the US from another country
- 011 is the country code used when calling internationally from within the US
What is a Country Code?
A country code is a numerical prefix that must be dialed before the area code and phone number when making an international phone call. Country codes allow calls to be routed correctly between different countries using the international phone network.
Every country around the world has been assigned a unique country code by the International Telecommunication Union (ITU). For example, the United Kingdom has a country code of 44, France has 33, Australia has 61, and Russia has 7. You can see a full list of all country codes here:
| Country | Country Code |
|---|---|
| United States | 1 |
| United Kingdom | 44 |
| France | 33 |
| Australia | 61 |
| Russia | 7 |
When calling internationally, the country code must always be entered first, followed by the area code and local number. This allows the telephone networks to route the call correctly to the destination country.
USA Country Code when Calling from Overseas
So when calling the United States from another country, the country code needed is 001. This tells the telephone network that the call is destined for the USA.
For example, to call the number 555-1234 in New York City from the UK, you would dial:
001 – 212 – 555 – 1234
Where 001 is the country code for the USA, 212 is the area code for Manhattan, and 555-1234 is the local phone number.
Without entering the 001 country code, the call would not be routed correctly to the United States from the UK phone network.
USA Country Code when Calling Internationally from within the US
When making an international call TO another country FROM within the United States, the country code used is 011.
For example, to call 44-20-1234-5678 in London from a phone in the US, you would dial:
011 – 44 – 20 – 12345678
Where 011 tells the US phone network that this is an international call. 44 is then the country code for the UK, 20 is the area code for London, and 12345678 is the local UK phone number.
Why are the Country Codes Different?
The reason the country codes are reversed when calling to and from the United States is due to the way the international phone networks are set up.
The USA was assigned country code 1 by the ITU early on when country codes were allocated. At that time, dialing systems only allowed for numbers up to 9 to be entered before the area code and local number. So callers from other countries dialed 1 to reach the US.
Later on, when dialing systems progressed to allow two digits before the phone number, international callers began prefixing country codes with 00. However, the USA kept its original country code of 1.
So callers to the US adopted 00 + 1 = 001 as the country code in order to comply with the updated international dialing system and allow calls to be routed properly.
Within the US, 011 was introduced as the new international dialing prefix, and this prefix has been retained even as dialing systems have advanced further.
How International Calls work
When making an international call between two countries, it passes through various telephone networks:
- The caller’s local phone network
- The domestic telephone network of the calling country
- International phone cables or satellites
- The domestic telephone network of the destination country
- The local phone network of the person being called
The country codes help route the call through these various networks to reach the correct final destination. The call routing works like this:
- The caller dials the international country code, area code, and phone number.
- The call is picked up by the local telephone exchange.
- The international country code tells this exchange it is an international call.
- The call is routed to the domestic telephone network’s international exchange.
- The international exchange routes the call via submarine cables or satellites to the destination country.
- The call passes through the destination country’s domestic telephone network.
- The area code and phone number allow the call to be routed to the specific local network and recipient.
So in summary, the originating country code tells the networks where to send the call when it leaves the caller’s country, while the destination country code indicates which networks should receive the call.
Mobile Country Codes
Mobile phones also use country codes in a similar way to landlines when it comes to international dialing. Each mobile carrier is assigned a network code after the country code.
For example, to call a mobile number in the UK starting with 07xxx xxxxxx from the US, you would dial:
011 – 44 – 7xxx xxxxxx
Where 44 is the country code for the UK and 07 is the mobile carrier code. An example mobile carrier code breakdown for the UK is:
| Mobile Carrier | Network Code |
|---|---|
| O2 | 07 |
| Vodafone | 07 |
| EE | 07 |
| Three | 07 |
So the mobile country code and carrier code combine to tell networks how to route international mobile calls correctly.
Special International Dialing Codes
There are also some special international dialing codes that are worth knowing about:
- 00 – Calling abroad from many European and other countries
- + – Indicates an international call, can often be used instead of 00
- 999 – Used to access emergency services in many countries
- 112 – Emergency number valid across GSM mobile networks globally
These codes provide universal shortcuts for international dialing or emergency access.
International Call Routing Process Summary
In summary, when making international phone calls:
- The originating country’s code indicates where the call is coming from
- The destination country’s code indicates which country should receive the call
- Country codes allow the call to be routed correctly between international networks
- Mobile calls use country codes plus carrier codes for routing
- Special codes like 00, + and 999 provide universal international dialing support
So while it may seem confusing at first, the use of country codes, mobile network codes, and special dialing prefixes allows calls to be directed correctly when dialing abroad or overseas.
Conclusion
To conclude:
- When calling the United States FROM another country, dial 001 before the area code and number
- When calling internationally TO another country FROM the United States, dial 011 before the country code, area code, and number
The variation is due to the way the international telephone system has evolved over time and the backwards compatibility introduced as dialing technology developed.
But the key points to remember are:
- 001 to call the US from abroad
- 011 when calling internationally from the US
Learning the international country codes and special prefixes like 00 and + can help you dial overseas calls correctly. But when calling to or from the United States, simply use 001 or 011 respectively at the start of the number.