Eliminating spam phone calls on iPhones

Most of you already know this, but there may be a few that don’t. I recently enabled “Silence Unknown Callers” on my wife’s iPhone, it works great. My wife’s been getting upwards of 50 spam calls a day, now they automatically go to voicemail. It’s obvious which of many of those are spam, since they only last for a few seconds. There are still some which last longer so she has to listen to those voice messages to make sure they are spam before deleting them.

No need for any subscription apps/services such as NoMoRobo, which we had been using before I found this setting.

Settings, phone, Silence Unknown Callers


I’m letting my voicemail fill up, because all I ever get on it are spam messages, and messages I would just as soon not have anyway. The dentist can just find another way to confirm my appointment.

Most of my family, friends, and business associates message me, and most of the ones who do call are in my address book.

Fortunately, I get few enough spam calls that I can just look at the phone when it rings, and if I don’t recognize the number, I don’t pick up. 50+ daily definitely requires more decisive action!

1 Like

I’ve had Silence Unknown Callers on since it was introduced. My phone rarely rings – maybe twice a week. Which is what it should do – never ring. My family and friends all stay in touch by text, and the occasional pre-arranged call. A couple times a month someone tries to call that I should speak with, and if they are persistent they leave a voicemail message that I return.

Now – Apple needs to do the same for Messages on iOS and macOS. It’s too many steps to block a number in Messages, which is exacerbated by the increasing number of texts asking for money, offering to buy my house, or sending texts when I explicitly opted out of texts. Messages is a mess.


I also block every spam number. I realize there is a limit to how effective this is but having blocked nearly 300 numbers and I almost never get a spam call, perhaps three per month.

Great tip. I’ve been using that feature for quite a while and, AFAIK, have never missed an important call. But it’s been my habit for years to immediately add people and businesses to my contact list if I ever expect to communicate with them again.

Businesses like Comcast get my Google Voice number, which I never answer. :grinning:


With the setting I mentioned yo no longer need to block any. It’s effectively done automatically for you.

Yes I know but blocking them gives me a sense of satisfaction. :slightly_smiling_face:


Now, you don’t need to do that any more. Turn on that setting and it doesn’t ring 50 times a day

1 Like

I should do this but many of my calls come from my company that arrive as Unknown Caller if they call from the office. If I switch this on, will I still get those calls? I assume not.

1 Like

I do the same until I grow weary of doing it.

I REALLY appreciate your sharing that info, Tony. All day long I am hounded by annoying phone calls. You can hear the silence then they transfer the call and usually I just hang up. Most of them I do not even answer. But there is just no end to it.

1 Like

Word of advice: don’t forget to (temporarily) disable this when you expect a phone call from someone (example: your doctor) who is using an unlisted number to protect her/his privacy.


correct, you will not received those call. A lot of companies has purposed disabled caller ID. So this is the drawback of using that setting

1 Like

My experience has been that I simply do not hear a ring indicator (neither audible nor vibratory) but the call comes in and is answered silently by voice mail. The iPhone reports it as a call that was silenced. If the caller chooses not to leave a message than I have missed a call, perhaps from my doctor or my plumber.


Another nice feature of Silence Unknown Callers is if the caller does have Caller ID and they do leave a voicemail where you now know they are legit, calling them back then makes that number a known caller, and future calls from that number will ring through.


You WILL still get the calls, the phone won’t ring though. It just goes to voice mail.

Sadly, this feature seems to be backfiring on me.
I got two calls from people who ARE in my phone list, and from that phone number too.
They both shows up as unknown.
The downside to “Silence Unknown Callers” is that you will have to listen to the voice mail messages to determine if they are spam or not. Many of them are likely to only last for a fe seconds, so they can easily be deleted without listening.

To play it safe though, listen to all of them in case someone leaves you a “Hey it’s me, call me back” message, which will only be a few seconds and can be mistaken as a quick spam call

All voicemails I receive are transcribed to some extent. Spam calls are obvious from this. Is this done by my carrier? I figured it was iOS.

I desperately want to have this turned on, but I have on at least 2 occasions missed calls from service technicians because I had forgotten to disable the setting. Also, I get a handful of SPAM text messages from people “interested” in buying my house every week, and blocking unknown callers doesn’t help with SMS. I don’t get why these house buying calls/texts make me so angry.

A few thoughts on this:

  • As many have noted, this setting can create issues for you. Sending every (non address book) caller to voicemail is too draconian for me. I get calls from technicians, clients (on different lines than they’ve used before), etc. etc.
  • While the “block this number” feature might be useful for a few minutes in the case of repeated calls, my understanding is that all these spammers are using spoofed numbers anyway. By blocking that number you aren’t preventing them from calling in the future AND there’s a slight chance a number will end up on your block list that ends up being a number you want to hear from. (This happened once to me. I wasn’t getting calls from a friend’s new cell phone and we couldn’t figure out why. The reason was that I’d blocked the number long ago because I received SPAM that appeared to be from that number. A rare case, I understand.)

I know the paid services were ruled out in the OP, but I do wonder why. I’ve had good results even with AT&T’s (free) Call Protect, and even better results with some of the paid solutions.

I set up a call for Apple support - and I was unable to pick it up because it kept going to voicemail, and eventually I realized it must be “silence unknown caller” setting - and I switched it off and finally they got through.

So now I enjoy leaving it on most of the time and the only thing I have to remember is to shut it off if I’m expecting a call from a company such as Apple or someone else that uses unlisted phone numbers.

1 Like