Line Access Restriction - #302-{Ext No}-{Line No}-{1=No Restriction / 2=Out Only / 3= In Only / 4=No Access} can set them to No Access on every line, then use #301 to remove the line appearances from the phone. They can't get dial tone by dialing Intercom codes.

Please consider if the phones will need to be able to dial 911 for emergencies. If so, leave the lines assigned to the extension, set #302 to Out Only, and use:

Disallowed Phone Number List #404-{List Number 1}-{Entry 01}-{Wild Card Character}
Disallowed List Assignment #405-{Ext No}-{List 1}-{1=Assigned}
Emergency Phone Number List #406-{Entry 01}-{911}

so they can get dial tone for outbound calls, but it disconnects them if they dial anything other than 911. You could set the Auto Line Select to Intercom first, forcing them to grab an outside line before dialing 911.

I love the detail TTT

have some pink

Joe
FHandw, ACSS, ACIS

https://www.millsidetc.com/