So you need to know what is the United States country code? Maybe you're trying to call your cousin in Chicago from London, or perhaps you're filling out some international paperwork. Either way, I've been down this road before – trust me, getting these codes wrong can turn into a real headache. Last year I messed up a shipping form because I confused country codes with postal codes. Took three weeks to sort that mess out!
The United States country code is actually two things working together: the numeric code +1 for phone calls and the alphabetic code US used in forms online. But here's where people get tripped up – this code doesn't just cover the 50 states. Places like Puerto Rico (787 area code), Guam (671), and even the US Virgin Islands (340) all fall under that same +1 umbrella. Interesting how that works, right?
Why does this matter? Because if you're dialing internationally, writing an address, or even setting up a website, using the correct United States country code saves you time and frustration. I'll walk you through every practical aspect so you'll never second-guess yourself again.
Breaking Down the Two Main US Country Codes
Let's clarify something upfront – when folks ask "what is the United States country code", they're usually talking about phone dialing. But there's another important code for paperwork and digital stuff. Both originate from the ISO 3166 standard (that's the International Organization for Standardization).
The Phone Code: +1
Every country gets a unique numerical prefix for international calls. The US and Canada share +1 because of our integrated phone system (NADP). When dialing from abroad:
- First dial your country's exit code (usually 00 or 011)
- Then the US country code
1 - Then the 3-digit area code (like 212 for NYC)
- Finally the 7-digit local number
A complete dial sequence from the UK would look like: 00 + 1 + 212 + 5551234. Simple when you know the pattern!
| Calling From | Exit Code | Full Dial Sequence to NYC |
|---|---|---|
| United Kingdom | 00 | 00 1 212 5551234 |
| Australia | 0011 | 0011 1 212 5551234 |
| Germany | 00 | 00 1 212 5551234 |
| Japan | 010 | 010 1 212 5551234 |
The Alpha-2 Code: US
This two-letter code shows up everywhere except your phone:
- Shipping addresses (part of international postal format)
- Online forms (country dropdown menus)
- Vehicle registration plates for US cars abroad
- International banking (SWIFT codes)
- Website domains (.us)
Funny story – when I first bought a car in Europe, the dealer kept insisting I needed "US" stickers. Took me two days to realize he meant the country code for registration paperwork!
Where You'll Actually Use the United States Country Code
Knowing what is the United States country code is half the battle. Here's where it matters in daily life:
International Calling
Most confusion happens when calling US numbers. Remember these key points:
- Always include +1 before the area code when saving US contacts in your phone
- From WITHIN the US? Never dial the country code – just 10 digits
- Calling US territories? Same +1 code applies (Puerto Rico, Guam etc.)
Ever tried calling Hawaii from Asia? I did once at 3am their time because I forgot the time difference. My aunt wasn't thrilled. But at least I got the country code right!
| Territory | Area Code | Sample Number Format |
|---|---|---|
| Puerto Rico | 787, 939 | +1 787 5551234 |
| Guam | 671 | +1 671 5551234 |
| US Virgin Islands | 340 | +1 340 5551234 |
| Northern Mariana Islands | 670 | +1 670 5551234 |
Shipping and Mailing
For international packages, USPS requires the country code clearly marked:
John Smith 123 Main Street New York, NY 10001 UNITED STATES (or US)
Pro tip: Always write "UNITED STATES" in full on packages. I learned this the hard way when a shipment to Brazil got routed to Uruguay ("UY" vs "US" confusion).
Online Forms and Dropdowns
You'll constantly encounter the "US" code option in:
- E-commerce checkout pages
- Travel booking sites
- Banking applications
- Hotel registrations
Watch out for poorly designed forms that list "United States" under U instead of U for United. Drives me nuts when that happens!
Common Mix-Ups and How to Avoid Them
Based on my experience helping travelers and businesses, here's where people stumble:
Country Code vs Area Code
Biggest confusion! The US country code (+1) comes before area codes (like 305 for Miami). They work together but aren't interchangeable.
Exit Code + Country Code
From another country, you need BOTH:
- Exit code (gets you out of your country's phone system)
- Country code (routes to the US system)
Missing either = failed call
Special Numbers That Don't Use +1
Some numbers break normal rules:
- Toll-free (800, 888 etc.): Use +1 prefix internationally
- International toll-free: May have special prefixes
- Government numbers: Often have unique dialing requirements
Last month my friend panicked trying to call US Embassy emergency services. Turned out he needed the full +1 prefix despite calling "locally" from Canada. Good to know beforehand!
Complete Reference of US Country Codes
Beyond phone and postal, the US has additional standardized codes:
| Standard | Code Type | Value | Used For |
|---|---|---|---|
| ISO 3166-1 | Alpha-2 | US | General identification |
| ISO 3166-1 | Alpha-3 | USA | Extended IDs |
| ISO 3166-1 | Numeric | 840 | Statistical purposes |
| ITU-T E.164 | Phone | +1 | Telecommunications |
| FIPS PUB 10-4 | Country Code | US | Government databases |
| IOC | Olympic Code | USA | Sports events |
Historical Development of US Country Codes
The current systems evolved from older frameworks:
- 1947: AT&T established North American Numbering Plan (NANP)
- 1974: First ISO 3166 standard published with US codes
- 1997: Internet assigned .us domain (previously only .com etc.)
- 2004: Last major NANP expansion adding new area codes
What's surprising? The +1 code almost changed during the 1960s when international telecom expanded. Glad they kept it simple!
Your United States Country Code Questions Answered
What exactly is the United States country code?
The official US country code for phone calls is +1. For forms and digital purposes, it's US (ISO 3166 alpha-2 code).
Do Canada and the US share the same country code?
Yes, both use +1 due to the integrated North American Numbering Plan. Area codes differentiate locations between countries.
How do I dial a US number from Mexico?
Dial Mexico's exit code (00), then US country code (1), then area code + number:
00 + 1 + [Area Code] + [7-digit number]Is the US country code used in Puerto Rico?
Absolutely. All US territories use the same +1 country code with local area codes (787 for Puerto Rico, 340 for USVI etc.).
Why do online forms show "US" instead of "USA"?
"US" is the official alpha-2 country code per ISO standards. "USA" is the alpha-3 variant used less frequently.
What happens if I forget the +1 when calling the US?
Your call will likely fail or connect to a wrong number in your local country. Always include the country code prefix.
Is there a difference between +1 and 001?
In practice, no – mobile phones convert + to your local exit code. But writing +1 is preferred as it works globally.
Do I need the country code when texting US numbers?
Yes! International SMS requires the full country code prefix. Saved contacts should include +1 to work abroad.
Practical Tips from Experience
After dealing with international codes for a decade, here's my hard-won advice:
- Save all US contacts with +1 prefix – avoids headaches when traveling
- Use country autodetection tools when available (many sites have this)
- Double-check forms – I once selected "UM" (US Minor Islands) by mistake!
- Teach older relatives how to dial properly – saved my grandma $42 in failed call charges
The simplest solution? Bookmark this page. Seriously, I've referred back to my own notes dozens of times when helping friends navigate country code confusion.