[Asterisk-Users] is '9' needed for "outside" numbers

[M.Hockings]

I have a small setup with half a dozen phones and a couple of soft 
phones that share a voip line and a pstn line.  Right now I have it 
configured to require a 9 prefix to dial to a number outside the 
building.  Where we are it is 10 digit dialing for even local numbers, 
the local dialable area codes start with 2,4,6 or 9 and our internal 
extensions all start with 3.  So I was thinking that I could make it 
more natural to just eliminate the requirement to dial the 9 prefix for 
an outside number?  Can anyone see problems with doing this?

Thanks for any opinions,

Mike