How do you know if someone blocked your number on a iPhone?

sassy
02.10.2019

Added (1). My boyfriend has a iPhone and his phone is just ringing then going to voicemail. He would always answer or call me back.

Guest
02.10.2019

You won't be able to call them.

What happens when you try to call someone who has blocked my number? I want to know if my friend has blocked my number. What would happen if they had blocked my number, and I tried to call them? Using an iPhone 5s, with the latest iOS update.
How would yoy know someone blocked your number? I have a regular phone and the person I texted has an IPhone. When I tried sending a text it said " The recipient that you are sending to has chosen not to receive messages. " What does that mean? My friend who also has an IPhone texted his number and he replied, but it had IMessage under it.
How would you know if someone has blocked you? I'm not on speaking terms with this person at the moment. Without calling, is there a way to know if he's blocked me? I have an iPhone and he has a Samsung. So when I text him, even if he gets it, it never says "delivered"
How to tell if someone blocked your number? Lets say someone has AT&T and they blocked your number as far as you sending them texts and calls goes, would you get a message saying they blocked you and would you get a message saying they blocked you if you tried calling them? The person that I'm wondering this about has an iPhone but I'm not sure which version.