How to Call a London Cell Phone from the US | Dial It Right

Dial a London mobile from the US as 011 44 7XXX XXXXXX, or save it as +44 7XXX XXXXXX on a smartphone.

The one step that trips people up in how to call a London cell phone from the US is the first zero. A UK mobile number written as 07XXX XXXXXX becomes 011 44 7XXX XXXXXX from a US landline, or +44 7XXX XXXXXX from a US cell phone.

A London cell phone does not have a London area code. UK mobile numbers are national numbers, so the person can live in London, Manchester, or Edinburgh and still have the same 07-style mobile format. London landlines are different: those usually begin with 020 inside the UK and become 011 44 20 from the United States.

Calling A London Mobile From The US: The Working Format

A London mobile phone should be dialed with the US international exit code, the UK country code, and the UK mobile number without its first zero. The full landline-style format is 011 44 7XXX XXXXXX.

Use this pattern when the number you were given starts with 07. For example, a UK mobile written locally as 07123 456789 becomes 011 44 7123 456789 from a US landline. On a US smartphone, the cleaner format is +44 7123 456789, because the plus sign tells the phone to place the correct international access code.

1. Start with 011 if you are dialing from a US landline.
2. Add 44, the country code for the United Kingdom.
3. Drop the first 0 from the UK mobile number.
4. Dial the remaining 10 digits, starting with 7.

Simple rule: 07 in the UK becomes +44 7 from outside the UK.

How Do You Dial The Number?

The easiest way to dial a London cell phone from a US mobile is to use the plus-sign format. Save the contact as +44 7XXX XXXXXX, and the same contact should work from the United States, the United Kingdom, and most other countries.

To get the plus sign on many smartphones, hold the 0 key until + appears. Then enter 44, followed by the UK mobile number after removing the first zero. Saving the number this way also helps with WhatsApp, iMessage, Signal, and other apps that read contacts in international format.

From a US landline, dial the longer version instead:

• US landline: 011 44 7XXX XXXXXX
• US cell phone: +44 7XXX XXXXXX
• Inside the UK: 07XXX XXXXXX

The FCC international calling tip sheet explains the US pattern for calling another country: dial 011, then the country code, then the rest of the phone number.

London Cell Phone Vs London Landline

A London cell phone starts with 07 inside the UK, while a London landline starts with 020. The international format changes both numbers, but the mobile number keeps the 7 and the landline keeps the 20.

The difference matters because London landlines carry a geographic area code and UK mobile numbers do not. A number beginning 020 points to the London area. A number beginning 07 points to a UK mobile service, not to a specific London neighborhood.

UK consumer information from the GOV.UK call charges page lists 07 as mobile numbers and separates 070 personal numbers, which can cost more and are easy to mistake for mobiles.

Why You Drop The First Zero

The first zero in a UK phone number is for calls made inside the United Kingdom. International callers use the country code 44 instead, so keeping the zero usually makes the call fail.

Think of the zero as a domestic routing prefix. The zero tells the UK phone network that the caller is dialing a national number. From the United States, the call reaches the UK through 44 first, so the domestic zero is no longer part of the number you dial.

Here are the common conversions:

• UK mobile 07123 456789 becomes +44 7123 456789.
• London landline 020 7946 0000 becomes +44 20 7946 0000.
• Manchester landline 0161 000 0000 becomes +44 161 000 0000.

Do not remove the 7 from a UK mobile number. Only remove the first 0. The 7 remains because it identifies the number as a UK mobile range.

What The Call May Cost

A call from the United States to a UK mobile may cost more than a domestic US call, and the exact price depends on your carrier or calling app. Check your plan before making a long call, because international voice rates can vary by provider and by whether you call from a landline, mobile phone, or internet calling service.

US carriers often separate international landline rates from international mobile rates. Some plans include discounted UK calls, while others charge by the minute. Wi-Fi calling through WhatsApp, FaceTime Audio, Signal, Skype, or a similar app can be cheaper when both people have data or Wi-Fi.

London is five hours ahead of New York during much of the year, eight hours ahead of Los Angeles, and six hours ahead of Chicago. The time gap changes briefly around daylight saving transitions, because the United States and United Kingdom do not always switch clocks on the same date.

What If The Call Still Fails?

A failed London mobile call usually comes from keeping the first zero, missing the country code, blocking international calls, or dialing a number that is not a regular mobile. Start by converting the number again from the beginning.

• Check the first digits. A normal UK mobile should look like +44 7 after conversion.
• Remove only one zero. Do not turn 07123 into 44 123; it should become 44 7123.
• Try the plus format. +44 7XXX XXXXXX is more reliable on smartphones than typing 011 manually.
• Ask for the number again. Missing one digit will stop the call, and UK mobile numbers usually have 11 digits in domestic format.
• Check your carrier settings. Some US plans block international calling until you enable it.
• Avoid 070 surprises. 070 looks close to 07, but it is a personal number range and may cost more.

Messaging the person first can also confirm whether the number is active. If WhatsApp recognizes +44 7XXX XXXXXX, the number is likely saved in a workable international format.

The Dialing Verdict

Use +44 7XXX XXXXXX on a US smartphone and 011 44 7XXX XXXXXX from a US landline. That is the clean answer for a London cell phone, because UK mobiles use the national 07 format rather than a London-only code.

For a London landline, use +44 20 followed by the local number, or 011 44 20 from a US landline. For a UK mobile, use +44 7 and the remaining digits. The one mistake to avoid is dialing both 44 and the first zero together, such as 011 44 07123 456789.

Save the contact as +44 7XXX XXXXXX if you will call or message the person more than once. That single format is easier to reuse, easier for apps to read, and less likely to fail when you travel.