Destination Codes not available...

[Davids38]

I am trying to setup some destination codes in my BCM 4.0 and I've noticed that some numbers are not available to me. Could someone please explain why they are not, and if there is anyway to clean it up so I have more of them available?
Here are the ones I cannot use, but that I would like to use:
1, 8, & 9.

Thank you!

 

[SEastTech]

you need the telco to change what they are sending if you are using a digital trunk...they are sending you 3 and you need them to send you 4...also check your hunt groups again...01-30 each of these will have a 4 digit dn assigned...i think default is 7xxx