Changed Their Phone Number: How to Know?

Here’s how to know if someone changed their phone number:

The easiest way is to call the number in question.

If it has been disconnected, you will receive an automated message from the carrier explaining as much. 

If for any reason you cannot call the number, phone listings, contacting the carrier, and other methods can answer your question.

So if you want to learn all about methods to determine whether someone changed their phone number, then you’re in the right place.

Keep reading!

Changed Their Phone Number: How to Know? (+ Vital Examples)

How Can You Determine If Someone Changed Their Number? (3 Methods)

Serious attractive young woman using mobile phone sitting at table in kitchen.

The most common method is calling the number, and that is explained in detail in the next section.

Ultimately, there are plenty of methods that work (all covered below). 

What you need is the means to check with the carrier network to see if the number you have connects to the person you have in mind.

Every one of these methods operates on that simple principle.

#1 Call the Number

Serious woman trying to call someone on the phone outdoors at autumn park.

Far and away, the easiest way to see if someone changed their number is to call them.

A few possibilities will arise, and each answers the question.

The first is that they might answer the phone.

If they do, you know that they didn’t change their number, and you’re good to go.

The other possibility is that someone else might answer their phone.

If so, you can ask directly.

If the new person is the owner of the number, you know the person you are trying to reach definitely changed their number.

The third possibility is that you will get an automated message from the phone service provider.

If you call a number that is not currently in use, you get some variation of the message, “the number you dialed cannot be reached.”

That tells you right away.

#2 Let It Go to Voicemail

Woman using smart phone in the night at home

Keep in mind that you don’t need anyone to answer the phone.

You can let it go to voicemail and still answer your question sufficiently.

If you get their voicemail message, it means that they have not changed their number.

When you change a phone number, your voicemail service changes numbers with you.

If you get the voicemail of a stranger, then you know.

The person in question changed their number, and the carrier recycled their phone number.

A whole new person has it now.

As for the “cannot be reached” message, it applies here too.

Sometimes, the phone will ring until it tries to go to voicemail.

It’s only at that point that you get the automated message. Regardless, the question is answered.

#3 Check Phone Listings

Hand marking listings on a phone book.

Contrary to popular belief, phone books and public directories are still a thing.

You can look at an updated directory.

Look up the phone number in question, and it should tell you who is attached to that number via phone registration.

Before you put too much stock into phone listings, it’s important to understand the risk.

Sometimes, directories are updated slowly.

If that happens, it’s hard to be sure if your information is reliable.

Here is how you can err on the side of caution.

If the listing shows a different owner of the phone number, you can trust that the person in question changed their number.

If the directory shows them as the owner, there’s still a chance they changed their number and the directory is out of date.

In this case, it’s best to pair this with another method.

What If They Blocked You?

Dissatisfied girl using smartphone indoors.

What if, for any reason, you can’t call the person in question. Well, there are a few options. 

First, you can use an unblocked number to call them. You don’t even need to have a conversation.

You’re just confirming a phone number. It’s pretty easy.

If that’s out of the question, you can try contacting their phone carrier.

The carrier cannot give out personal information regarding their customers. 

But, if you supply a name and a phone number, they should be able to give you a yes or a no as to whether or not the name and number match.

They likely cannot tell you any more than that, and you need to be able to demonstrate that you already know both the name and number that you are checking.

Can You Find the New Number? (4 Ways)

Serious young woman using mobile phone while sitting on sofa.

Let’s not talk about why you don’t have the new number.

Plenty of times, this is an innocuous thing where people lose touch.

Sometimes it’s more complicated, and all of that is beyond the scope of this discussion. 

Instead, let us suffice it to say that you are trying to reach someone, and the number you have is out of date.

This is how you can overcome that obstacle.

#1 Try Other Contact Methods

Young woman putting letter into envelope at table in cafe.

If this person is a friend, family member, or colleague, there’s a good chance that you have other ways to contact them.

You can hit them up on their email or a social media platform where you have connected before.

You can try snail mail.

You can even consider the ultimate taboo of visiting a person at their home.

As long as you have a relationship where that is reasonable, stop by and ask about their phone number.

It’s always best to go this route first and ask them directly for their contact information.

It can help you avoid uncomfortable social faux pas.

#2 Reach Out to Common Contacts

Handsome man and beautiful woman talking outdoor looking at phone.

If you don’t have the ability to contact them directly, then you can move on to common contacts.

Ask a mutual friend or contact if they can help you get in touch. 

It’s entirely possible that multiple people have lost touch with the person you are trying to reach, but if you give it a little effort, this will frequently work.

#3 Use Social Media

Young woman using a digital tablet while standing in front of windows in office

This may come at the risk of invoking the term “social media stalker,” but there are harmless ways to do this.

If you are not direct contacts on social media, you probably have common contacts.

This is a way to more thoroughly go through the previous method.

If common contacts don’t work, you can try a deep dive.

For the sake of avoiding awkwardness, let’s leave those methods for another day.

#4 Pay for a Service

Woman using credit card for online purchase.

There are professional services that exist for exactly this kind of scenario.

You can find them online, and they will help you look up a phone number for an individual. 

They do charge money for the service, but plenty of them are reputable companies.

You can enlist their help, and they can assist you in tracking down a person’s phone number.


  • Theresa McDonough

    Tech entrepreneur and founder of Tech Medic, who has become a prominent advocate for the Right to Repair movement. She has testified before the US Federal Trade Commission and been featured on CBS Sunday Morning, helping influence change within the tech industry.

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