How to dial area codes
To dial a US number, dial the area code and the seven-digit local number, adding 1 first for a long-distance call within North America or for a call from outside the United States. In an overlay area, dial all ten digits even for a local call.
Step 1: Find the area code
Start with the full number, not just the local part. The first three digits are the area code, and they decide which region the call goes to. If you are unsure what region a code covers, check it on the area code finder (/what-area-code-is-this/) or on its code page before you dial. This matters when a city has more than one code, for example 213 for central Los Angeles and 310 for the Westside and South Bay.
Step 2: Dial local calls with ten digits in overlay areas
In an overlay area, where two or more codes serve the same region, dial the area code plus the seven-digit number for every call, including a call to a neighbour on the same street. Leaving the code off will not connect the call, because the network cannot tell which of the overlay codes you meant. With only one code, local rules can differ, so check that code’s page. Do not assume a rule from another state or another code, because dialing rules follow the numbering area, not the state as a whole.
Step 3: Dial long-distance calls within North America
For a long-distance call to another US number, dial 1, then the area code, then the seven-digit number. The 1 is the trunk prefix for North American long-distance dialing, and it is used even when the call stays within the same country. The area code is still required, because the seven-digit number alone is not unique across the country: the same seven digits can exist under many different area codes. Check the code page’s time zone first if calling across zones.
Step 4: Dial from outside the United States
From outside the United States, dial your country’s international exit code, then 1 for the United States, then the area code, then the seven-digit number. On a mobile phone, the plus sign can replace the exit code, giving +1 followed by the area code and local number. The 1 after the exit code is the country code for the United States within the North American Numbering Plan, not part of the area code itself. Do not drop the area code when dialling internationally: it is still required to reach the right region.
Common mistakes to avoid
The most common mistake is dialling only seven digits in an overlay area, which fails because the code is missing. The second is using the wrong code for a city with several codes. The third is treating the code as proof of where the caller is: a kept number, an internet call, or a spoofed caller ID can show a code that does not match the caller’s present location. If a caller asks for money, codes, or account access, hang up and call back on a number you trust, whatever code was shown.
Frequently asked questions
Do I always need to dial the area code?
In an overlay area, yes, even for local calls. Elsewhere, check that code’s page rather than assuming one rule fits everywhere.
What does the 1 before an area code mean?
Within North America it is the long-distance trunk prefix, and from outside the United States it is the country code for the United States. It is not part of the three-digit area code.
Can I dial a US number with just seven digits from abroad?
No. From abroad you need the exit code, the country code 1, the area code, and the seven-digit number. Seven digits alone do not identify a region.
What if I dial the wrong area code?
You will reach a different numbering area or the call will fail. Check the code on the finder tool or the code page and dial again with the correct code.
Sources: NANPA Area Code Search tool; NANPA planning letters cited on the Batch 1 code pages.
Based on a recent search of NANPA and official sources.
This website provides general information about North American area codes, compiled from public sources including NANPA. It is not affiliated with or endorsed by the FCC, NANPA or any telephone carrier. Area code details can change; confirm with your carrier or the official NANPA website. This site does not identify callers or phone owners.