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Comment by the_mar | Hacker News Reader

Boy do i have a lifehack for you. Buy a phone number with a random area code, like ohio or something, all the spam calls come from surrounding area codes.

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There's a useful iOS app called Number Shield that lets you block all calls coming from numbers that match the first six digits of your phone number. That's the most common spoofing technique, so it really does help.

E.g. if your number is (555)555-1234 it'll block anything from (555)555-0000 to (555)555-9999.

https://apps.apple.com/us/app/number-shield/id1319082167

It's funny how 30 years ago, probably 90% of my actual phone calls were with numbers that matched the first six digits of my own.

Now that number is 0%.

So true! Area codes (and first three digits) used to indicate where you were. Now, more often than not, they indicate where you bought your first cell phone, i.e. where you lived around the year 2000 for us oldsters.

I wish I could block all calls from UK. Since brexit all spam calls that comes through are from there sadly

It was closer to 50% for me since there were two (overlaid) exchanges in my neighborhood. I still remember about a dozen phone numbers of friends from when I was growing up.

Can confirm, bought it years ago, the only app that allows me to easily block full range of numbers. I'm in France and work just fine.

I didn't want to over-promise, having only used it inside the USA's phone system. :D

This is a great idea; unfortunately now I have dozens of voicemails a week from these numbers instead of just calls. Any option to prevent them leaving voicemail?

Just be warned this will also block legitimate numbers.

You can give it access to your contacts so it'll exclude them, or whitelist specific patterns if you want.

Begone is better than Number Shield plus its free.

https://apps.apple.com/us/app/begone-call-blocker/id15968181...

I've been using Number Shield since long before Begone existed, so I can't really comment on their comparison.

...though the creator of Begone will hopefully realize that every entry in its version-history starting with that same rant about fake ad campaigns is making it look more sketchy than ignoring the issue would.

Interesting. Anyone knows what API they are using or how they are achieving this? It’d have thought that this would not be possible.

From a user perspective it’s similar to content blockers for Safari.

Settings > Phone > Call Blocking & Identification

its kinda sad that we need an app for that ngl

Does that app transmit data anywhere?

Not that I know of? The privacy statement on that App Store page says it collects usage data and diagnostics, and that neither are linked to you personally.

One of the things I've noticed recently is that spam call numbers have gotten smarter -- somehow they're figuring out numbers corresponding to regions that I spend time in that aren't related to my area code or central exchange...

Meta smarter

I love this. Used to live in SF and kept the 415 number after moving. Any of the bay area area codes get instant silenced (manually). And any number from my current area code I know to answer as it is legit

I noticed spam callers are even copying the first 3 numbers of my cell phone.

555-555-1234

All the 5s match my number, which hasn’t happened since I used to live in a small town. That always makes me do a double check but it’s also easier to ignore.

this wouldn't work for me. most of the spam calls that I get are from other random cities/states that are far from my area code.

But then my calls will come from the random area code too. It’d be neat if you could do a dual phone number, where your CID on outbound calls shows as your local area code, but you give out the foreign area code for inbound calls.

But then you mess up callbacks.

You misunderstand slightly. All the calls from the area code matching your phone number are more likely to be spam (spammers matching you to appear legit). So unless you call people in that particular area, you won't be matching their area code, so you won't look like a spammer. And unless you happen to know a lot of people in that area, you won't get calls from that area that appear to be spam.

> So unless you call people in that particular area, you won't be matching their area code, so you won't look like a spammer

You're misunderstanding them too, I suspect. One could equally assume that a call coming from an area code they've never been to, 5 states away is spam - so this trick works if you do not make a lot of calls.

> One could equally assume that a call coming from an area code they've never been to, 5 states away is spam

Not equally. I have an area code from the opposite coast. If I get a call from that area code, it is 100% spam. Spammers just love outing themselves by spoofing the same area code of the person they are calling.

A call from any other area code is only 30% chance of being spam.

Your missing the point. Spammers call you from a spoofed number so that you think its someone near you based on the area code. I lived just a town over an invisible line in 2009, and ordered a new phone, and got an area code that the only other person I know that has a number in that area code is my wife. (920)

the ONLY calls that call me from that area code are spammers. if I get calls from any other area code, only 20% or so are spammers. Others are sales/marketing for IT companies, etc, and calls from one of the 2 area codes that cover my area where I actually live are usually all local businesses, etc. If I had to guess, I would say 85-90% of the 'spam callers' call and spoof the 920 area code when they dial me. that drastically cuts down on my automated messages about a car warranty that is about to expire.

> But then my calls will come from the random area code too

Nobody will care. Everybody's cell number is just a record of where they lived when they got their first phone; people you call will have you in their contact list most likely.

I must be extra lucky because I receive calls from all over the US and beyond. Just yesterday I received one from Brazil.

I have a 972 number. Caller ID recently made it look like I'd received calls from Israel and Peru, but it was had dropped the US country code (+1) and making it look like the calls were from +971 (Israel) and +51x (Peru).

OK, so basically if you have a 650-64 Palo Alto number, you'd block half the VCs in the world. If you have a lower Manhattan 212 number, you'd block a quarter of all finance recruiters? (granted, the latter has moved to Linked In)

Yeah, I did this. But it's not enough. Most phone number blocking apps get really slow blocking a couple of area codes. Number Shield loads _very_ slowly on my iPhone 13 with just 919 and 984 blocked. But they do fire prober calls from other locations too. The interesting thing is that they never actually say anything on the phone or in text. It's solely some sort of DoS against me. Weird.

In my location the spammer spoofs the numbers of calls that get picked up or go to voicemail.

I assume they do this to muddy the block lists that get used to filter their calls.

I know this because every now and then I will get up to 5 or so calls or texts of people claiming I called them.

Actually, the more-telling part of the number is the exchange. They'll often match yours, which is dumb as hell.

In the age where most phones are mobile, this whole "scheme" is pitifully ignorant.

Spamming, like many other things in life, is a field of bleeding edge technology. :) They were not using your area code a decade back, then they realized your area code works better - it probably did for a while. When it loses effectiveness, they will move on to other patterns they have discovered.

Also, A/B testing is not just for good guys.

I got a Google Voice number with an area code that's way out in the boonies somewhere. It's super easy for me to identify spam, and to prevent it by not giving my real number to almost anyone.

Yep. I have had my number for, forever and I'm now in a different area code. Pretty much everything that comes in from that original area code is spam.

Just have the US start sending missiles to spam call centers and people will stop real quick.

People answer phone numbers that their phone doesn’t tell them who it is?

Huh.

This works until you get calls from DC.

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