How to block spam calls on iPhone: 3 ways that work

There are three built-in ways to block spam calls on iPhone, and they are worth setting up before you install anything. This page covers those first, then what a blocking app adds, and the one limit no call blocker will tell you about.

Block spam calls on iPhone with what iOS already does

Block one number

In Phone → Recents, tap the i beside the call, scroll down, and choose Block this Caller. That number can no longer call, text or FaceTime you. It is the right tool for a specific nuisance and the wrong tool for spam, for reasons below.

Silence unknown callers

Settings → Apps → Phone → Silence Unknown Callers (on older versions of iOS, Settings → Phone). Anyone not in your contacts, recent outgoing calls or Siri suggestions goes straight to voicemail without ringing.

This is the most effective free setting on the phone, and it is also the bluntest. The delivery driver outside your building, the clinic calling back, a new client returning your email — all silenced. Plenty of people turn it on, miss something that mattered, and turn it off again. That single trade-off is the reason call-blocking apps exist.

Report it, and check with your carrier

Reporting junk in Messages feeds Apple and your carrier. Most carriers also run their own network-level blocking, often free and off by default — worth ten minutes on their site, because a call stopped at the network never reaches your phone at all.

Why blocking numbers one at a time loses

Spam operations rotate numbers. Blocking the one that just called you is closing a door in a building with a thousand doors — you are always one behind, and the list you build never catches up.

What actually works is blocking at the level the spammers operate at: a range rather than a number. Telemarketing traffic tends to come from allocated blocks, and in some countries those blocks are published — Brazil, for instance, requires telemarketers to call from the 0303 prefix, so one rule covers the entire category. iOS cannot do this on its own.

What a call-blocking app can actually do

Apple does not let apps answer, screen or listen to your calls. What it provides instead is a Call Directory extension: the app hands iOS two lists — numbers to block outright, and numbers to label with a name like “Likely spam” so you can decide before answering — and then steps out of the way.

iOS holds those lists and does the matching itself, in its own process. That design is why call blocking on iPhone is private: the app is never told who is calling you.

The limit nobody advertises

Because the app hands over a list and leaves, it never finds out which calls were blocked. There is no callback, no count, no log. iOS does not report back.

So when a call blocker shows you “1,284 calls blocked this month”, it is not counting blocked calls, because it cannot. It is counting how many numbers are on its list, or estimating from a shared database, or counting something else and presenting it as a shield. Worth knowing before you judge two apps on that number.

The honest measure of a call blocker is how few unwanted calls actually ring — which you can only judge by living with it for a fortnight.

Junk texts are a separate problem

SMS uses a different mechanism again — a message filter extension, which iOS consults for messages from people not in your contacts, and which can route them into the junk folder before they reach you. Same principle: the extension decides, iOS files the message, and the sorting happens on the phone.

Where pluris fits

pluris does the parts iOS leaves out. It blocks numbers outright or labels them so you can decide; it blocks whole prefixes when the spam comes from a range rather than a number, including the Brazilian 0303 telemarketing range with one switch; it routes junk SMS to the junk folder and sorts promotional from transactional; and it has a Meeting Mode for when you want everything quiet.

The free tier is a working allowance rather than a trial: 5 blocked numbers, 5 labelled numbers and 3 prefix rules, plus 12 keywords per SMS category. Prefix rules are capped lower than the rest because one of them can cover millions of numbers. Pro removes the caps.

All of the matching runs on your iPhone. There is no account, no sign-in and no server holding your lists. The one thing pluris fetches from the internet is a public, community-maintained list of known spam numbers, used to seed the on-device block list — nothing about you is sent with it. The pluris privacy policy sets out the detail.

pluris is on the App Store. It is free, needs iOS 18.6 or later, and ships in 22 languages. Download it here.