Posted on June 29, 2023 in Technology

What is Number Spoofing?

Have you ever had someone call you, but they seem to think you called them first? Or have you ever picked up a call from someone that you thought was on your contacts list, only to discover someone else on the line?

It’s not the plot of a B-Grade horror movie: it’s number spoofing.

If you’re one of many people now telecommuting due to the Covid-19 pandemic, you may have access to a VOIP – a Voice Over Internet Protocol, which basically just makes it possible to make phone calls directly from your computer (Microsoft Teams is a common one). These first popped up around 2005 and have only improved as the internet has. However, the downside to this fantastic convenience is that it’s possible to send false or intentionally misleading information over the line to trick another person into picking up, either with a false caller ID or a false number, altogether. The false number trick is particularly annoying because when the person calls that number back, the number’s actual owner has no idea what they’re talking about! Two separate people get caught up in the fuss of a scam call.

Race to the Bottom

It gets worse than mere confusion, though – scammers, at a point, were impersonating both the police and the callee. They’d call the person with their fake Caller ID indicating that they were ‘police’, and then call the station with the same Caller ID as the person they’d just called, as a form of harassment. Police call back or show up about this bogus call, and the person may believe that the police really did call them – which may lead to them hiding or fleeing ‘arrest’ over whatever the spoofer called threatening arrest for. This makes them more likely to respond to harassing calls about payment in the future.

VOIPs also made it easier for some people to harass people they just didn’t like, no money involved. One man had a SWAT team bust in on him, and prank calls using the same ‘Police’ or ‘Jail’ trick as before were rampant, although those were less concerning if the person calling had the common sense to quit before their friend panicked. Assuming they were a friend.

The opportunities to torment people with this tech are endless. Perhaps even worse now that spoofing can be combined with AI voice tech, since it’s gotten good enough to fake another person’s voice in real time.


Payday loan companies were known for this misrepresentation (any business that tried would have to be the right intersection of ‘scummy’ and ‘local’ for this to be feasible), although they weren’t the only people to abuse Caller ID. Credit Card scammers would use any number of false IDs to get the other person to pick up the line, ranging from ‘Ambulance’ and ‘Hospital’ to ‘Son’ and ‘Teachers Phone’. Some of these obviously don’t work all the time – not everybody has a son, or needs to answer the phone for a teacher – but for the ones that did pick up, it became more likely that they’d fall victim to the scam.

This was particularly effective against the elderly, who may not be able to tell that the person on the other end of the phone isn’t ‘Grandson’ or ‘Niece’, for any number of reasons – and they end up wiring money to a fraudster. This was so prevalent for a while that AARP released an article on it, telling their readers that you can no longer trust Caller ID. And still, the scam gets people who get caught up in the fear of a loved one in danger or discomfort.

Long Story Short

Don’t trust caller ID, and if someone calls you to tell you that they’re in jail, and they need you to bail them out by wiring money: call the courthouse, call other relatives, do something to verify that they’re actually in trouble. The same goes for credit card ‘warnings’ or warnings about back-taxes. The IRS will send a letter before they call or show up at your house! They’ve got a guide here.

Sources left as links for convenience: