How to Block incoming calls without third party apps- 2

You can block one or more phone numbers using this trick.

If you try to block calls sometime your network carrier will apply charges for this.Else you are using a third party app it will always running in backgroud and take ram,cpu and more issues.Some apps block calls after ringing.

This will help you to block calls without any app.

 Go to phone book.Now create a contact( you can give it a name like 'blacklist' or any other name.) and add phone number or numbers what you want to block.
Now scroll down.Then you can see a check box like 'send calls directly to voicemail'. Tick and save it.

When that person call you,call will be diverted to voicemail number.

If you want to completely block him or her,
  Go call settings> Voicemail settings under voicemail give  a wrong number(like 1234567) and save it.He will not disturb you again.