There are some clues to check whether someone has blocked your number or not. It may include some unusual messages or how swiftly your phone call transfers to voice mail. The best way is to ask the person directly whether he or she has blocked you or not. There may some other issues. Some other problems also create the same signs as blocking. For example, if the person you are trying to contact has switched off his mobile phone or they have turned on Do Not Disturb mode.
There are some clues that indicates you whether someone has blocked your number or not.
Unusual Messages
If you receive some unusual messages while contacting a person then it may be possible that he or she has blocked, you. If you call him or her repeatedly and receive the same unusual messages, then it is the confirmation of your blocking. But sometimes same messages may be a result of some other reasons as described above.
Number of rings
If you listen merely one ring before your call alter to voicemail, this is a good sign that you have been blocked. But first ring can also turn to voicemail if the same person has turned on the Do not Disturb mode.
Busy signal
Before your call is dropped, if you receive busy signal then it may be an indication that your number have been blacklisted.
What should you do if you have a doubt that someone has blocked your number?
By using the setting option of your mobile, hide your number.
Call them from someone else phone and ask them directly regarding it.
Utilize *67 to conceal your number from their caller id.
How to check whether you have been blocked on iPhone or not?
Send the courteous message if you get the notification or it is written that message is delivered then this means you are not blocked. But if you do not receive such kind of things then absolutely you are blocked. Then for further confirmation, call him or her. If calls change to voicemail at once, then send voicemail to check it.