The following information is simply an example of an extension numbering schema.  The advantages of adopting a schema for your company will help when you support multiple clients a day, to see the same organizational setup across all of your clients domains. NOTE:  Keep in mind, you should use a 3 or 4 digit extension.   Avoid the reserved number spaces like 411, 611, 911, 933 and special functions.   Visit the article above for more info.Schema ConsiderationsOrganizationally speaking, you may want to consider if the client has more than one (1) location.  When you visit a hotel, or a hospital, typically the first number represents what floor you need, followed by a room number.   You could consider this same type of numbering schema to create your extensions 1000's for the first location, and 2000's for the 2nd building or location.  Example Schemas100 - 199Users extensions 200 - 299More available extension range300 - 399Routing Users / Ring Groups / General Voice Mail etc.400 - 499Conference Bridge extensions(Except for 411)500 - 599Auto Attendants600 - 699Call Queues(Except for 611) 700 - 799Reserved Space for Parking FunctionsNote: System default uses extensions 700-729 only. To extend call parks to 730-799, please send a request to the Control Tower team by emailing support@skyswitch.com.800 - 899Available extension range1000 - 1999Users extensions in Building 12000 - 2999Users extensions in Building 2See this article for other reserved number spaces.