Can we change extension 800 funcationality to another extension?

Hello,

We have setup a system where each location uses 100 extensions and assigned 100, 200, 300 etc to the operators.
800 of course is a reserved extentsion. Is there any way for me to assign that to another number line 899?

Thanks!

Almost all extensions apart from 0 are arbitrary just plan your dialing to.suit and don’t accept any default that interferes as you add.endpointa if you use the guim