When you block someone on iPhone, you silently cut off their ability to reach you through Apple’s built‑in calling and messaging, but they don’t get a clear “you’ve been blocked” warning.

What actually happens (Quick Scoop)

  • Their regular calls to you go straight to voicemail or fail to ring through on your side.
  • If they leave a voicemail, it’s moved into a separate “Blocked Messages” / filtered section, not your main voicemail inbox.
  • Their SMS and iMessage texts are not delivered to your phone at all; you don’t see them and can’t reply.
  • Their FaceTime calls never reach you; your phone doesn’t ring or show any missed call.
  • On their side it usually looks “normal”: texts may still show as sent, calls may ring or jump to voicemail, so there’s no obvious sign they’ve been blocked.
  • Blocking only covers Apple’s own apps (Phone, Messages, FaceTime); they can still contact you via WhatsApp, Telegram, Instagram, etc. unless you also block them there.
  • Your existing chat history with them stays on your device; blocking doesn’t erase past messages or call logs.

Mini sections

1. Calls and voicemail

  • Incoming calls from a blocked number usually go straight to voicemail or stop after a very short ring, without your iPhone ever lighting up.
  • If they leave a message, it’s stored in a separate blocked/filtered area so you won’t see it in your normal voicemail list.

In practice, to them it often just looks like you’re always busy or ignoring their calls.

2. Text messages and iMessage

  • Their SMS and iMessage attempts are silently dropped: no banner, no sound, nothing appears in your Messages app.
  • On their phone, the message usually still shows as “sent” (sometimes just without the usual delivery/read feedback), so they don’t get a specific “blocked” error.

An important detail: messages that never reached you while they were blocked are not “released” or restored if you later unblock them; they’re just gone.

3. FaceTime and Apple services

  • FaceTime audio and video calls from a blocked contact never get through; your device stays completely quiet.
  • To the caller, it can look like it’s ringing or failing to connect, but they don’t get a message that you blocked them.

Blocking at the iOS level generally applies across Phone, Messages, and FaceTime for that number/contact.

4. Third‑party apps (WhatsApp, etc.)

  • Blocking a number on your iPhone does not automatically block that person on WhatsApp, Instagram, Facebook Messenger, Telegram, or other third‑party apps.
  • If you want to completely cut contact, you need to block or restrict them individually in each of those apps as well.

So even if they can’t call or text your number directly, they may still reach you through social or chat apps until you block them there too.

5. What they see vs. what you see

From their side:

  • Texts look like they were sent; they usually don’t see a special failure notice.
  • Calls ring or jump to voicemail, which feels similar to you ignoring or being unreachable.
  • There is no official “You have been blocked” alert anywhere.

From your side:

  • No calls, texts, or FaceTime alerts from them at all.
  • Optional: a hidden/filtered voicemail section might contain any messages they leave.
  • Your old conversations remain in Messages unless you manually delete them.

Quick forum-style TL;DR

“If I block someone on iPhone, will they know?”
Not directly. Their calls go to voicemail, texts never show up on your phone, FaceTime doesn’t connect, and they don’t get a clear notice — it just feels like you never pick up.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.