Spoofing Phone Number

spoofing phone number

What is spoofing a phone number?

Like most people, you probably screen your calls by checking caller ID. People do this to avoid spam calls from marketers, as well as other reasons. But what if someone disguises their phone number to avoid being detected as spam, just to get you to answer the call?

That’s called caller ID spoofing – the caller spoofs a phone number that you may recognize as a normal call. In other words, the displayed caller ID isn’t the real phone number, but rather a phone number that is probably local to your area.

There are several reasons for spoofing phone numbers, and some are actually legal. However, phone number spoofing has become a mainstay for scammers who want to get in touch with you for fraudulent reasons.

A scammer could be in entirely different country, searching for victims in Australia. However, you likely won’t answer a call that your caller ID displays as being from another country. As a result, the International scammer uses caller ID spoofing to appear as if the call is coming from someone in your country, or even your city. That way, the chances of you answering the call increases significantly, making it easier to perpetrate any planned fraud. 

There’s a distinct difference you should not, however, involving a similar scam. Spoofing phone numbers is different from a stolen phone number, where the scammer ports your number over to another telco or SIM in order to control any accounts that use your number as verification. Because of their similarities and differences, we will also address how to recover a stolen phone number in this post. Read on to find out.

How to tell if someone is spoofing your phone number

Calling Line Identification (CLI) refers to caller ID, which identifies callers on a display screen to enable you decide whether to answer the call or not. Virtually all telcos offer this service as part of their SIM plan, because of how helpful it has become in spotting spam calls and other undesired calls.

However, there are ways a caller can disguise their number, which we’ve already described as spoofing. This is typically done by CLI overstamping, which is actually legal but can be used for illegal activity.

In order to detect a spoofed phone number, you’ll have to be attentive during the call. If a caller demands personal information like complete credit card details, personal identification numbers (PIN), money, gift cards, etc., you’re likely dealing with a spoofed phone number and not a real one.

Who is spoofing my number?

Whenever a scammer spoofs a phone number to contact someone, there’s a good chance that the spoofed phone number actually belongs to a real person who has no idea that their number has been spoofed. In that case, if you miss a call from a spoofed phone number, you might call back and the real owner of the number will pick up the phone without any knowledge of calling.

For the true owner of the spoofed number, receiving multiple call backs from numbers you never dialed can become frustrating. Imagine fielding numerous calls a day from people you don’t know, who all claim you gave them a call; or people who may have reported your phone number to law enforcement because it was spoofed and used to defraud. If this happens to you, then your phone number has likely been spoofed by someone else.

Spoofing text messages

Unfortunately, spoofing doesn’t end with phone calls – scammers can also spoof text messages. This is referred to as SMS spoofing, where the perpetrator sends text messages to people using a spoofed phone number or replacing the number with alphanumeric text.

You can detect SMS spoofing in ways similar to caller ID spoofing – just pay attention to content of the text messages and any personal information requests.

Is spoofing a number illegal?

Well, it depends. Some companies actually spoof phone numbers for legitimate reasons, making it perfectly legal. However, what makes spoofing a number illegal is the purpose of it – for instance, if the reason for spoofing is to scam, then it becomes entirely illegal.

In other words, CLI overstamping is not illegal, but when it is being don with malicious intent or for fraud, it becomes illegal, and referred to as caller ID spoofing or phone number spoofing.

What to do if your number has been spoofed

If your phone number has been spoofed, there’s not much you can do to change that because it has already happened. However, you can simply explain to anyone who calls you with the belief that you called them, that you never did call and that your phone number was likely spoofed.

In this case, the best you can do is report it to your telco. Let them know that someone has spoofed your number. And if you get calls from unidentified numbers as a result of your number being spoofed, simply ignore those calls or block them entirely.

What to do if your number has been stolen

There is another phenomenon which involves your phone number being stolen. This is a step beyond spoofing phone numbers, because a stolen phone number has been completely taken over by the scammer.

Criminals steal phone numbers by orchestrating unauthorized ports or SIM swaps. They can contact a new telco and purchase a SIM with your details, pretend to be you, and request that your existing phone number be ported over from your former telco. They can also purchase a new SIM from your existing telco, pretend to be you, and ask that the number be swapped to the new SIM or SIM plan

If your number has been stolen, you likely won’t be able to use it to make or receive calls and SMS. You likely won’t see any signal bars, which might be replace by the SOS symbol.

Here are some tips on what to do if your phone number is stolen:

  • Contact the police to report your number has been stolen
  • Contact all financial institutions that use your number as identification, and inform them. Also change your passwords in case you use two-factor identification to log in to sensitive accounts. 
  • Contact your phone company immediately and tell them your phone number has likely been stolen.
  • Demand that your telco remove porting options
  • Record a voicemail greeting informing callers that your number has been spoofed or stolen
  • Change your phone number

Final words – My personal experience with phone number spoofing

If your phone number has been spoofed or stolen, you’re not alone. Having had it happen to me, I did some research and there is a lot of good information about how to deal with such an unsettling phenomenon and to make your account safe again. The key step is to contact your phone company as quickly as you can and tell them it’s happened to you. They will guide you through the process. 

I test a lot of SIMs and phone companies, simply because I work at a mobile phone SIM plan comparison site. When my number was spoofed, I happened to be with Telstra. I engaged them through their ‘My Telstra’ (previously Telstra 24×7) app and they were as helpful as they could be. 

In the end, we decided to put some notes on my account so no-one could port my number out of Telstra, which seemed like the biggest risk. Once ‘they’ have your mobile number under their control, (if that is their plan by spoofing your number) they can start to do real harm by setting up accounts and using your phone number as the second factor in ID confirmation. 

More than anything though, the experience left me feeling off kilter and slightly uneasy. Any event with proximity to Identify Theft is obviously worrying for any normal person.

Neil Aitken

Having worked in 3 countries for 4 telcos on both voice and data products, Neil is in a position to give you the inside track. Get beyond the marketing messages to the best plan for you.