Changing Exchange Server 2013 UM dial plan for Unified Messaging enabled users

I was recently told by our telephony engineer that we needed to create a new UM dial plan with the URI Type set as SIP URI for our internal users that are using Exchange Unified Messaging for voicemail because of the migration from Exchange 2007 to 2013:

The GUI did not provide a way to simply move user accounts from one UM dial plan to another so I resorted to PowerShell cmdlets and thought it would be a good idea to document the process then blog it so I can reference it in the future.

Step #1 – Identify users in the legacy UM dial plan

Begin by identifying the users that you intend on moving from the legacy UM dial plan with the following cmdlet:

Get-UMMailbox | where {$_.UMDialPlan -eq "Mintflower"} | Format-Table –Wrap -AutoSize

The list displayed from the cmdlet above will list the users currently enabled for Unified Messaging with their dial plan set to the legacy one.

Step #2 – Disable Unified Messaging for users in legacy dial plan while retaining configuration

Next, execute the following cmdlet to disable the users for unified messaging but retain their configuration such as extensions:

Get-UMMailbox | where {$_.UMDialPlan -eq "Mintflower"} | Disable-UMMailbox -KeepProperties $True -confirm:$false

The cmdlet will produce output similar to the following listing the users that have been affected:

**Note that if the list above continues more users than the screen buffer has, pipe out the output with > C:\UMusers.txt

Document the PrimarySMTPAddress field for each user in the output above.

Step #3 – Enable users for Unified Messaging assigned to the new UM dial plan

With the users’ PrimarySMTPAddress field list, execute the following for each user:

Enable-UMMailbox -Identity enorville@ccs.bm -UMMailboxPolicy “Bakery Lane Default Policy”

Substitute the email address and the UMMailboxPolicy as required.