Why spam calls come from similar numbers to your phone number
mobile spam · 7 comments · 250 words · read ~475 times.
In the last few months, I've received dozens of spam calls which appear to come from a similar phone number to mine.
If my number is 07700 900 123 I get calls from 07700 900 124 or 07700 900 456
Here's my working theory on why spammers do this. Americans.
In the UK, there's a separate "area code" for mobile phones. If a number starts 07 then it is mobile (it's a bit more complicated than that).
In the USA, there's no cellular prefix. If you buy a SIM card in Las Vegas, you'll probably get a 702 number - at least, I did when I last visited.
Some of the area codes in the USA cover tiny geographic areas.
Spammers know this. They bet that if they call +1-555-867-5309 from +1-555-867-5409 the person will believe the spammer is local to them. Possibly even a neighbour. It is a weak form of social engineering attack. You're more likely to trust someone local than a distant stranger.
In the UK this doesn't work. Not because we don't trust our neighbours, but because our mobile numbers aren't tied to a specific geography.
Cultural hegemony can be an effective anti-shibboleth!
@Edent galaxy brain spam callers: calls you from your own number
@Edent @vfrmedia tbh it doesn’t work in the US either, except on old people(the joke is everyone 40 or younger doesn’t answer their cell phone if they don’t recognize the actual number, and this type of spam just means we’re even less likely to answer)
Michael S says:
This social engineering worked once on me here in the UK recently (luckily all I did was call the number back only to discover the person with that number never made the call).
My partner and I have UK phone numbers that differ by one digit as we bought the SIMs from the same shop at the same time 20 years ago - so when I got a spam call from a number with only two digits different, the long history of self-conditioning around locality and similar numbers was ready to be activated.
Funny, I just noticed this today. (My number starts 07901)
It’s not often I hate on Google but when I listened to their IO announcement about Call Screening I got excited. Except that over 1 year later it only works in the USA and in English. We are just not important enough elsewhere. Flame on. https://partnerdash.google.com/apps/simulator/#screen-your-calls?l=en&model=Pixel_4 Consequently I have to field multiple spam calls weekly. And indeed they are all from a number ‘close to mine’. grrr.
Yes, I thought the same thing! I’d probably pick up the phone if they used a landline number from my local area, but from a mobile number it feels very “uncanny valley” to me.
Yes, that sounds about right to me. I’ve noticed the same thing. Next time someone asks, I’ll point them to this explanation!