Can I block a specific number from my business landline?

[Thingsthatgo]

I need the line to be open to calls all day, but I am getting intimidating calls from a business contact and it's constant interruption. I will be talking to the police about it, but in the meantime is there a way to block his number?

I would contact your telephone service provider and ask them how to do it, they should be able to tell you.

Ok thank you.