You can tell if someone blocked you on an iPhone without texting by observing if calls go to voicemail after one ring and texts show "Not Delivered," but these signs can also mean their phone is off or on Airplane Mode; consistent patterns over time (calls always one ring, texts never delivered) strongly suggest a block, with the key clue being the call behavior: one ring then voicemail usually means blocked, while no rings and straight to voicemail means off/DND, though it's not 100% certain without asking, as their settings (DND, Airplane Mode) mimic a block.
Here are the easiest ways to tell if someone has blocked you on their phone:
An easy way of knowing you've been blocked is to send a message with read receipts on. If the message doesn't say delivered that means you're blocked. Calling is slightly different, it rings a couple times and goes to voicemail. You can leave a message which they will get but they won't receive a notification for it.
You can suspect someone blocked you on an iPhone if calls go straight to voicemail (maybe after one ring) and iMessages don't show "Delivered" or "Read" receipts, but these signs can also mean their phone is off; the most reliable test is trying to call them using a different number or *67 to hide your caller ID, and if it rings normally on their end but goes to voicemail from your real number, you're likely blocked.
The system does not send any notification to the blocked person. However, many iPhone users may be able to deduce that you've blocked them. This is because of the iMessage text “status” feature on iPhones. When two iMessage users text each other, the message status shows “Delivered” when it arrives.
If you're blocked by someone, your calls will go straight to voicemail, and your voicemail messages will head to the “Blocked” section immediately. The other person won't receive your calls, won't be notified you called, and won't see a badge for your voicemail.
SMS is a cellular carrier technology where Apple controls iMessage. If a person blocks you on iMessage, then they won't get any of your texts at all.
Muting helps you ignore someone without preventing them from doing anything. Blocking someone prevents them from messaging you, commenting on your observations, identifying your observations, and otherwise interacting with you on iNaturalist.
When someone blocks you, their profile photo may disappear or stay the same for a long time. Sometimes, you might still see an old photo because your phone has saved it. If you tap the photo and it disappears, this can be a clue that you are blocked. However, missing profile details do not always mean blocking.
This star code will unblock your caller ID for a single outgoing call if you have previously used *61 to block caller ID for all outbound calls.
If you've been using iMessage with another iPhone user, your text bubbles are blue. If someone blocks you through iMessage, your texts will appear as green — the same bubble color you'll see in a thread with a non-iPhone user. Check your text thread to see if your messages recently went from blue to green.
Another way to tell if you have been blocked is through social media. If you have been previously connected via social media and you no longer see their posts or pictures, then there's a high chance that you've been blocked.
Top 4 Ways to Text Someone Who Blocked You on iPhone
If your call goes to voicemail after several rings or if they answer, you've likely been blocked. This method isn't foolproof, though. If the person you're calling has silenced unknown callers, they won't see your text or hear your call.
Practical signs someone may have muted you
Messages remain “sent” or “delivered” but never get quick replies: If your messages consistently show delivered but the person doesn't reply for long stretches while they remain active elsewhere, muting could be the reason.
Soft Block on Instagram: A More Subtle Option
Messages and Calls:
If your number is blocked and you attempt to send an iMessage to the recipient who blocked you, the blue bubble will still appear and it will look like your message actually was sent (although it won't show a “Delivered” confirmation).
What Apple Officially Says
If you're not blocked, the phone should ring anywhere from three to twelve times before going to voicemail. A blocked number may ring only once and then go to voicemail. (NOTE: It's also possible that the person is on another call, has their phone turned off, has a low battery, or has it set to airplane mode.)
One of the quickest ways to know if someone has blocked your number is to call them. If your call goes to voicemail after one ring, this could be a sign that your number has been blocked.