US Phone Number Format & Examples [With Country Code and Area Codes] (2024)

Whether you’re a UK business contacting American partners or simply ringing friends across the pond, correctly formatting US telephone numbers is crucial for successful calls. With unique area codes, local number conventions, and special service codes, understanding proper US phone number structure can be confusing.

This guide will break down how American phone numbers are formatted, common techniques like adding separators, standard lengths, proper inclusion of area code, and mistakes to avoid so your calls connect every time.

How to Call the USA in 5 Steps (With Examples)

Calling the USA from the UK is relatively straightforward, but there are a few key things to keep in mind. We’ll walk you through the process step-by-step, with examples to help you along the way.

1. Note the US International Exit Code (+1 / 001)

The international exit code for the USA is +1 or 001. This is the code you need to dial to signal to your phone carrier that you are making an international call.

2. Obtain the US Country Code (1)

The country code for the USA is 1. This is the code that tells your phone carrier which country you are trying to call.

3. Check the US Area Code

In the US telephone numbering plan, the area code is always the first part of a phone number after the exit and country code. Area codes are 3 digits long and written enclosed in parentheses. For example:

• (555)

This (NPA) area code format is standard across all types of US phone numbers. Leaving out the area code or using a different format like 555- is not valid in the US system. The area code is required to route calls to the correct geographic region or toll-free service.

Some common examples of properly formatted US area codes:

• (212) – New York City
• (747) – Los Angeles, CA
• (817) – Fort Worth, TX
• (404) – Atlanta, GA

4. Double-Check the 7-Digit Local Phone Number

After the 3-digit area code, the next portion of a US telephone number is the 7-digit local subscriber number. This is assigned by the phone carrier based on the particular central office (CO) exchange.

The standard format is to write the 7 digits separated into a 3-digit prefix and 4-digit line number. For example:

• (555) 123-4567

This 7-digit local phone number format is consistent for landlines and mobile numbers. Omitting the area code and just dialling the 7-digit number will connect a call within the same local exchange, but not internationally.

Some examples:

• (212) 555-1212 – Local NYC number
• (030) 123-4567 – Local Boston number

5. Ensure the Correct US Phone Number Format

For long distance calls in the US, the full 10-digit phone number is dialled – including the area code. Long distance numbers are formatted starting with the digit 1, then the 3-digit area code, followed by the 7-digit local number. For example:

• 1-(555)-123-4567

The 1+ area code format helps the phone system recognise that the call is long distance and should be routed between exchanges.

Some long distance US phone number examples:

• 1-(212)-555-1212 – Long distance call from California
• 1-(404)-123-4567 – Long distance call from New York

All US Area Codes

In the US, area codes are geographical markers consisting of three digits that come before local phone numbers. These area codes can vary across states, with some having one or two, and others having dozens.

Below are all the US area codes across all 50 states:

The Current US Phone Number Format

The US phone number differs quite drastically from that of the UK, so we’ve compiled everything you need to know about the current US phone number format.

Telephone Area Codes

The current telephone numbering system in the US uses area codes as the first 3 digits of a phone number. Area codes are also known as Numbering Plan Areas (NPAs). These 3-digit prefixes correspond to specific geographic regions and allow routing calls to the correct destination.

The original North American Numbering Plan (NANP) defined 86 NPAs from 201 to 916. Four area codes (640, 740, 850 and 950) were later added as the number of phones grew. Today there are over 350 valid area codes assigned by the North American Numbering Plan Administrator (NANPA).

When a region starts running low on assignable phone numbers within an area code, providers can implement an area code overlay or split. An overlay assigns a new area code to the same region, while a split divides the region into multiple area codes.

For example, the 917 area code was overlaid in New York City in 1992 as 212 numbers ran out. Area code splits are less common now due to number pooling conservation efforts.

Local Telephone Exchanges

The next 3 digits after the area code represent the central office (CO) code which identifies the local telephone exchange. For landlines, this specifies the switching centre connecting the phone to the PSTN.

Early telephone exchanges were named with alphabetic prefixes. As numbers digitised, these letter prefixes translated into numeric counterparts. For example, the Pennsylvania exchange KLondike-1234 became 555-1234.

Today, central office codes are assigned in blocks to providers within each area code. Larger CO blocks are reserved for dense metro areas while rural regions may get smaller CO code assignments. The specific CO code determines the provider and physical infrastructure serving a customer.

Separators

While not required, separators like hyphens, periods and parentheses are often used in US phone numbers to improve readability.

Common formats include:

• (555) 555-1212
• (555) 555.1212
• 555-555-1212
• 555.555.1212

These separators help differentiate the area code, central office code, and line number. Using spaces, such as (555) 555 1212, is not an acceptable format. Parentheses around the area code are the most common format in the US numbering plan. Consistent separator use makes numbers easier to interpret at a glance.

Toll-Free Numbering

Toll-free numbers in the US use 800, 888, 877, 866 and other dedicated area codes. They provide freephone service by reversing carrier charges from call recipients to call originators. AT&T introduced the 800 area code for toll-free numbers in 1966.

Toll-free numbers are managed by the Somos Inc SMS/800 Registry. Companies register keywords through Responsible Organisations (RespOrgs) which Somos converts into assigned toll-free numbers. For example, 1-800-FLOWERS.

Over 10,000 RespOrgs participate in toll-free number administration. Toll-free numbers can be used for customer service, order taking, marketing and other business purposes. Vanity numbers help build brand identity.

Special US Phone Numbers and Codes

The US telephone network utilises various special numbers and N11 codes to provide easy access to essential services, information, and assistance. These short numerical codes offer convenience and memorability.

Emergency and Helpline Numbers

The most well-known special telephone number is 911, which connects to emergency dispatch services for fire, police, and ambulance. 911 was designated as the universal emergency number in the US in 1968, though some cities were already using it in the 1960s.

Calling 911 is free from any phone and will provide the dispatcher with the caller’s location. Enhanced 911 (E911) also transmits cell phone location data to aid response. As it’s simple and widely known, 911 is credited with saving countless lives.

Various 3-digit community helpline numbers also exist. The 211 code operates in most states to connect callers with health and human services referrals. 311 provides non-emergency municipal services in many cities. 511 offers local traffic and transportation information.

These easy to remember numbers provide vital community access. Various local authorities manage helplines like 211, 311 and 511 at the regional level.

Telecommunication Relay Services

711 connects callers to Telecommunication Relay Services (TRS) which enable people who are deaf, hard of hearing, deaf-blind, or speech-disabled to place calls.

TRS centres provide relay operators who assist callers to type messages back and forth or interpret via video remote interpreting. State TRS programs work with the FCC to ensure functionally equivalent communication access.

Some examples of TRS services accessible through 711 include:

• TTY/TDD relay for typed conversations.
• Voice carry over for speech-disabled users.
• Hearing carry over for hearing-impaired users.
• Speech-to-speech relay for clear interpretation.

Other Special Service Codes

The US telephone network utilises additional N11 codes to provide various public services:

• 411 – Directory assistance to request phone number listings.
• 511 – Location-based traffic and transportation updates.
• 611 – Customer service contact for phone carriers.
• 711 – Telecommunication relay services for disabled users.
• 811 – Call before you dig contact to avoid underground utility lines.
• 911 – Emergency services dispatch number.

N11 numbers are reserved as easy to remember 3-digit codes for essential services. They can be dialled nationwide based on service availability but FCC permission is required for assignments.

Special telephone numbers and N11 codes allow fast, convenient access to critical services for the public good. Whether requesting emergency medical aid, finding a local business number, or accessing relay services for those with disabilities, these carefully designated codes support communication for everyone.

Common US Phone Number Format Issues

While the US telephone numbering plan is straightforward in theory, users often make mistakes formatting numbers that lead to invalid dialling. Being aware of common errors can help ensure your phone numbers are properly formatted.

Missing Area Codes

One of the most frequent phone number formatting errors is omitting the 3-digit area code. For any US phone number to be valid, the area code must be included.

Some try dialling just the 7-digit local number out of habit or assumption it’s a local exchange call. However, excluding the area code will result in a failed call in most cases. The full 10-digit number is required.

Wrong Separators

While not required, separators are commonly used in US telephone numbers to aid readability. However, inconsistent or incorrect separator use can create invalid formats.

Some common separator mistakes include:

• Reversing separators like using .(555).555-1212 instead of (555).555.1212
• Using spaces instead of hyphens, periods or parentheses
• Not using any separators in lengthy numbers
• Using multiple separator types inconsistently

Standard conventions should be followed, such as parentheses around the area code and consistent hyphen, period, or space use in the local number.

Typos and Transpositions

Like any numeric identifiers, telephone numbers are prone to inadvertent typos and transposition errors. A few examples:

• Swapping digits – 123-4576 instead of 123-4567
• Missing digits – (555) 555-212 instead of (555) 555-1212
• Adding extra digits – (555) 555-12314567
• Mistyping digits – (555) 556-1212 instead of (555) 555-1212

Care should be taken when manually entering a telephone number to double check accuracy. Before dialling, verify the number matches the proper 10-digit US telephone format with area code and legitimate exchange.

The History and Evolution of US Telephone Numbers

Now we’ve explained the US phone number format, you might be interested to know how it has progressed over the years. We’ll discuss switchboards, regional number plans, and the creation of the North American numbering plan.

Early Telephone Switchboard Systems

In the early days of telephony in the late 1800s, calls were routed manually by human operators working at switchboards. These switchboard operators would physically connect calls by plugging cables into jacks on the board. The Bell System pioneered manual switchboard exchanges in the US, with the first switchboard opened in New Haven, Connecticut in 1878.

As phone adoption grew rapidly in the early 20th century, manual phone exchanges likewise expanded across the country. By the 1920s, there were over 10,000 manual exchanges in the Bell System alone. However, this manual system didn’t scale well as call volume increased. Operators had to memorise subscriber phone numbers and work extremely quickly plugging cables.

Development of Regional Numbering Plans

Independent telephone companies began assigning numeric phone numbers to subscribers in the early 1900s to improve efficiency. These early numbering plans were regional, with each area developing its own system. Numbers were short – often just 2-4 digits – based on the capacity of local exchanges.

For example, one town may have used 2xxx while a neighbouring town used 3xxx. This patchwork of fragmented regional numbering plans became a major obstacle as more calls crossed area boundaries. By the 1920s, around 400 incompatible numbering systems existed nationwide. Efforts emerged to unify systems, including early experiments in 4 and 5 digit numbers.

Creation of the North American Numbering Plan

In the 1940s, AT&T and the Bell System developed the North American Numbering Plan (NANP) to streamline telephone numbering across the country and Canada. After gaining FCC approval, AT&T rolled out the unified NANP in stages between 1947-57.

The NANP established 86 regional Numbering Plan Areas (NPAs) which each contained central office prefixes. This allowed for universal direct dialling between regions. Initial NPAs had area codes 201-916, with 555 reserved as a fictional code. The NANP format expanded numbers to 7 digits (NPA + local number) and later 10 digits (area code + 7-digit number) as demand grew.

The NANP was a seminal milestone in telephony, facilitating nationwide calling and seamless growth. The plan has sustained over 50 years later, adapting to increasing phone numbers with new area codes and overlays. Though modified, the NANP numbering hierarchy remains the foundation of US and Canadian phone systems today.

Final Thoughts from UK vs. USA

Whether you’re looking to call a US phone number, or you’re preparing in case you do, hopefully this guide gives you the tools you need to do so.

If you found this article helpful, you might be interested to read UK vs. US keyboard layout differences.