What's the country calling code for the United States?

When dialling someone in New York, Los Angeles, or Houston from the UK, there are a few important steps you must follow to make sure you get connected.

This guide is designed to clear up any confusion. We explain the strict rules of the North American Numbering Plan (NANP), walk you through the exact dialling steps, and share tips on saving money and avoiding common mistakes, whether you’re calling from home or using a Revolut eSIM while travelling.

Understanding the international code for the United States

Making an international call requires a specific, multi-step sequence. The full sequence is essential to direct your call and ensure a successful connection.

The role of the international access code (00 or +)

Your call must begin with an international access code, also known as an exit code. This tells your phone company that the next digits are for a country outside of your own.

• Calling from a mobile phone: you should always start your sequence with +. This allows your phone company to redirect your call out of your country. Since most customers use mobile phones, this makes things simpler.
• Calling from a landline: you must start with 00 instead of +. This is the standard international exit code for the UK and many other countries.

The mandatory US country code

Immediately following your exit code, you must dial the country code. In this case, you use the US dialling code, 1.

Whether you begin with the landline exit code or the mobile + symbol, the combined sequence is the international dialling code for the US.

• Mobile full start: +1

Example: if the US mobile number is (305) 998-7766, you'd dial +1 305 998 7766.

• Landline full start: 00 1

Example: if the US landline number is (212) 555-1234, you'd dial 00 1 212 555 1234.

Understanding this format is the first step in mastering the US phone number format.

How to call a US phone number from the UK

The United States uses a consistent 10-digit national numbering plan. Unlike some countries, there are no domestic 0s to drop before the area code. The total length of the number, including the 3-digit area code, is always 10 digits.

The general format you need to follow is:

• UK exit code or +
• United States country code: 1
• 3-digit area code
• 7-digit local number

Dialling US landlines and mobiles: the 10-digit structure

In the US, there's no technical difference between how you dial a landline and a mobile number. Both require a full 10-digit sequence (area code followed by local number).

For example, if your contact in Chicago provides the number (312) 987 6543, the international dialling code would be +1 312 987 6543.

How to save your US contacts

For seamless calling and messaging, especially when you're travelling or using apps, you should always save your US contacts in the international format.

Always save the contact starting with the + symbol and the country code.

Example: +1 212 555 1234.

This standard format ensures that apps and services correctly interpret the number, removing any need to manually adjust the format or exit code, regardless of your current location.

Why didn't my call to the United States work?

Common dialling mistakes

If you tried to call a US contact and your call failed, you've most likely made a common dialling mistake. Even with the US country code entered correctly, other small mistakes in the sequence can stop your call from going to plan.

Mistake 1: forgetting the area code

Since US numbers are often shared as just the 7-digit local number (e.g. 555-1234), it's easy to forget the mandatory 3-digit area code when dialling from abroad.

Make sure you dial the country code followed by a 10-digit number. If your contact only provided a 7-digit number, you must ask for the corresponding 3-digit area code.

Mistake 2: using the wrong exit code

Using an incorrect UK exit code or forgetting the +1 code will stop your call from making it to the US. Make sure you check the full number you've dialled before making your call.

Mistake 3: the hidden costs of international calling

If you're using a standard UK phone plan, calls to someone in the US can incur substantial per-minute charges.

Make sure you check your network provider's specific international calling rates to the US before you dial. This is especially important if you're travelling there from the UK. Relying on UK network roaming for calls and data in the US can be expensive, which leads many customers to seek alternatives. Our United States eSIM data plan offers a digital solution, allowing you to instantly buy data plans in-app and bypass those costly traditional roaming fees.

What's the best time to call someone in the United States?

The United States spans 6 main time zones, making time difference a major factor when planning your call. Most states observe Daylight Savings Time (DST), which generally aligns with the UK's BST schedule, meaning the difference in hours remains consistent throughout the year.

Navigating US time zones

These are 4 of the time zones in continental US:

When to call for business vs personal reasons

• Personal calls: the best time for UK customers to call contacts on the US East Coast (EDT) is the UK late afternoon/early evening (4–7pm BST). This is late morning/early afternoon in the US (11am–2pm EDT). For the West Coast (PDT), calling during the evening in the UK (6–9pm BST) reaches the US late morning/early afternoon (10am–1pm PDT).
• Business calls: for professional communication, aim for the UK afternoon (3–5pm BST) to ensure overlap with the US East Coast workday, or 5pm BST to catch the start of the West Coast workday.

Other US phone number types (toll-free and emergency)

It's useful to know about 2 other types of numbers you might encounter:

• Toll-free numbers: these typically start with 800, 888, 877, 866, 855, or 844. These numbers cost nothing to call from within the US but will likely incur charges or fail to connect when dialled internationally using the international dialling code for the US.
• Emergency number: the national emergency number in the United States is 911. This number isn't diallable from overseas.

Staying connected internationally: our eSIM for US travel

If you're heading to the US, managing your data and communication should be as easy as knowing the international code. Excessive data roaming charges are a thing of the past when you travel with us.

Eliminating roaming fees with a prepaid eSIM

Traditional roaming is expensive and unpredictable, and buying a local SIM card in the US is inconvenient and involves physical insertion. Our eSIMs offer a digital solution that solves both problems.

A Revolut eSIM allows you to buy prepaid data packages in-app, without needing to buy a physical SIM card. This ensures you have high-speed data access from the moment you land, eliminating the stress of searching for WiFi or a local mobile shop.

You can instantly top up your data plan in-app, keeping you connected for maps, messaging, and internet calling services without steep international charges.

Benefits beyond calling: data plans for US travel

We offer flexible eSIM data plans that suit different travel durations and needs.

• Our global eSIM: for customers travelling across multiple countries (e.g. the US, Canada, Mexico), a North American or global eSIM plan might offer the most flexibility
• Our eSIM for the US: if you're only planning on exploring the United States, a regional eSIM plan may be more cost-effective

Sending and managing money in the United States from the UK

Managing money across borders can be challenging, especially for travellers and those dealing with the US dollar (USD).

International money transfers: sending USD seamlessly

If you need to send money to a US bank account for services, tuition, or family support, we simplify the process with international transfers. You can execute transfers directly from your account, with competitive exchange rates for the US dollar (USD). This helps you easily manage your money across borders, ensuring your recipient receives it as efficiently as possible.

Exchanging and spending: using your Revolut card in the US

While you're travelling, it's important to make sure you're getting the best exchange rate on the US dollar so you can stick to your budget. Using a Revolut card can help you do this effectively.

You can hold and exchange USD at competitive exchange rates in-app. When you spend using your card in the United States, we automatically use the best available rate, so you aren't hit with the excessive fees that traditional banks often charge for foreign transactions.

Frequently asked questions (FAQs)

What's the difference between +1 and 001?

Both +1 and 001 represent the country code of the United States. The difference is in how you dial them: 00 is the international exit code specifically for a UK landline, while the + symbol is the international access code used on mobile phones. Always use +1 on a mobile phone.

Can I text a US phone number using +1?

Yes. Text messaging follows the same format as voice calls. You must begin with +1 followed by the 10-digit number (area code followed by the local number).

How long should a US phone number be?

When dialled internationally (after the +1 code), a US phone number must be 10 digits long.

How to get started with Revolut

Ready to simplify your international travel and spending? Here's how you can use Revolut to stay connected and manage your money across the globe:

1. Sign up: open your account in minutes through the app
2. Order your card: get your physical card and instantly access global spending power with competitive exchange rates
3. Activate your eSIM: purchase and install your eSIM digitally to get data in the United States and over 100 countries, helping you avoid unexpected roaming charges
4. Send money seamlessly: make fast, cost-effective international transfers in USD and many other currencies in-app

You can learn more about how Revolut is helping customers connect with our other regional calling guides, such as the calling code for Canada, the calling code for France, and the calling code for India.

Other guides are available for the calling code for Ireland, the calling code for Malaysia, the calling code for Mexico, the calling code for Nigeria, the calling code for UK, and the calling code for Australia.

The information provided is accurate as of 10 October 2025.

Exchange fees, remittance fees, fair usage limits, and T&Cs apply.