557 Area Code — Missouri
557 is a North American Numbering Plan area code for Missouri, the United States. It covers about 903,029 people in 2 towns and 69 ZIP codes, including Saint Louis and Saint Ann.
| Field | Value |
|---|---|
| Area code | 557 |
| Country | United States (+1) |
| State / province | Missouri |
| Type | Shares its towns with 314 |
| Time zone | Central |
| Population covered | 903,029 |
| Towns covered | 2 |
| ZIP codes | 69 |
| Approx. centre | 38.642, -90.287 |
Where area code 557 is used
Area code 557 is assigned to Missouri, the United States, inside the North American Numbering Plan. Numbers in the code are written (557) NXX-XXXX at home and +1 557 NXX-XXXX when dialled from outside Canada and the United States. Since the NANP moved to 10-digit dialling you must always include the area code, even for a local call.
Other area codes in this footprint: 314. They serve towns in the same territory, so a single street can contain numbers from more than one code. That is normal in the NANP and does not change how you dial.
Towns and cities in area code 557
The 2 towns below are the largest in the 557 footprint, ranked by population. Every one of them links to its own page with the full list of area codes and ZIP codes for that town.
| Town | County | Population | ZIP codes |
|---|---|---|---|
| Saint Louis | St. Louis city | 887,236 | 68 |
| Saint Ann | St. Louis County | 15,793 | 1 |
Counties covered
| County | ZIP codes |
|---|---|
| St. Louis city | 38 |
| St. Louis County | 31 |
Other area codes serving the same towns
Nearby area codes
How to dial area code 557
- Within North America: 557 + 7-digit number (557-NXX-XXXX). The leading 1 is optional on a mobile phone and required on most landlines for long-distance.
- From abroad: your country's international prefix, then 1, then 557, then the 7-digit number — for example 00 1 557 NXX-XXXX from most of Europe.
Frequently asked questions
What area code is 557?
557 is a North American Numbering Plan area code assigned to Missouri, the United States. It covers about 903,029 people in 2 towns.
Is 557 a US or Canadian area code?
557 is a United States area code. Canada and the United States share the +1 country code, so both are part of the same numbering plan.
What time zone is area code 557 in?
Area code 557 is in the Central time zone.
Do I have to dial 10 digits?
Yes. Every NANP call now requires the area code plus the seven-digit number, even for a local call.