AD Account Will Not Create If Duplicate First Name & Second Name - powershell

Question

I am creating a script to create users on a domain for one of my clients (NHS in the UK), however it currently refuses to create the AD User & exchange account if the user has a First & Second Name that Already Exists within the AD.
I have already bypassed username duplication by adding a number onto the end of the usernames if they already exist. However, if the first / second name is duplicated it will not create the account.
$DisplayName = $Surname + " " + $GivenName
$Mail = $GivenName + "." + $Surname + "#" + "royalberkshire.nhs.uk"
$MailAlias = $GivenName + "." + $Surname + "#" + $DNSRoot2
$SInitial = $Surname[0]
$Initial = $GivenName[0]
$SAMAccountName = $Surname + "" + $Initial
$SAMAccountLower = $SAMAccountName.ToLower()
$UserPrincipalName = $Surname+$Initial
$HD = "U"
$HDir = "\\RBHFILRED002\"
$AC = "Users_01$\"
$DH = "Users_02$\"
$IM = "Users_03$\"
$NS = "Users_04$\"
$TZ = "Users_05$\"
$Folder = if ($SInitial -in 'a','b','c'){$AC}
elseif ($SInitial -in 'd','e','f', 'g','h'){$DH}
elseif ($SInitial -in 'i','j','k', 'l','m'){$IM}
elseif ($SInitial -in 'n','o','p', 'q','r','s'){$NS}
else {$TZ}
$group1 = "zz Everyone"
$group2 = "Safeboot Domain Users"
$defaultname = $SAMAccountName
$email = $GivenName + "." + $Surname
$i = 1
cls
while ((Get-ADUser -Identity $SAMAccountName -ErrorAction SilentlyContinue) -ne $null) {
$SamAccountName = $defaultname + [string]$i
$Mail = $email + [string]$i + "#" + "royalberkshire.nhs.uk"
$i++
}
$NewUserParams = #{
Path = "OU=Users,OU=RBFT,DC=rbbh-tr,DC=nhs,DC=uk"
SamAccountName = $SAMAccountName
Name = $DisplayName
DisplayName = $DisplayName
GivenName = $GivenName
Surname = $Surname
EmailAddress = $Mail
UserPrincipalName = "$SAMAccountName#rbbh-tr.nhs.uk"
Title = $title
HomeDrive = $HomeDrive
HomeDirectory = "$HDir$Folder$SAMAccountName"
Description = $Description
ChangePasswordAtLogon = $true
PasswordNeverExpires = $false
AccountPassword = $defpassword
Enabled = $true
}
New-ADUser #NewUserParams
Add-ADGroupMember -Identity $group1 -Members $SAMAccountName
Start-Sleep -s 10
Add-ADGroupMember -Identity $group2 -Members $SAMAccountName
cls
echo "Please Wait Whilst We Find The AD Account & Create The Exchange Mailbox.."
Start-Sleep -s 30
Enable-Mailbox -Identity $SAMAccountName
cls
Any Ideas?
EDIT 1 - Error output:
Name : Microsoft.Exchange.Management.PowerShell.E2010
PSVersion : 1.0
Description : Admin Tasks for the Exchange Server
Name : Microsoft.Exchange.Management.Powershell.Support
PSVersion : 1.0
Description : Support Tasks for the Exchange Server
This tool is to be used for creating User Accounts for the RBFT Domain under
Ultima Business Solutions only. If this applies, please hit any key to continue.
Get-ADUser : Cannot find an object with identity: 'TimmsJ1' under: 'DC=rbbh-tr,DC=nhs,DC=uk'. At C:\Users\timmsj\Desktop\Scripts\User_Creation\RBFT_UC_Dev.ps1:140 char:9
+ While ((Get-ADUser -Identity $SAMAccountName -ErrorAction SilentlyCon ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (TimmsJ1:ADUser) [Get-ADUser], ADIdentityNotFoundException
+ FullyQualifiedErrorId : Cannot find an object with identity: 'TimmsJ1' u nder: 'DC=rbbh-tr,DC=nhs,DC=uk'.,Microsoft.ActiveDirectory.Management.Comm ands.GetADUser
New-ADUser : An attempt was made to add an object to the directory with a name that is already in use At C:\Users\timmsj\Desktop\Scripts\User_Creation\RBFT_UC_Dev.ps1:166 char:1
+ New-ADUser #NewUserParams
+ ~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (CN=Timms James,...tr,DC=nhs,DC=uk:String) [New-ADUser], ADException
+ FullyQualifiedErrorId : An attempt was made to add an object to the dire ctory with a name that is already in use,Microsoft.ActiveDirectory.Managem ent.Commands.NewADUser
Add-ADGroupMember : Cannot find an object with identity: 'TimmsJ1' under: 'DC=rbbh-tr,DC=nhs,DC=uk'.
At C:\Users\timmsj\Desktop\Scripts\User_Creation\RBFT_UC_Dev.ps1:167 char:1
+ Add-ADGroupMember -Identity $group1 -Members $SAMAccountName
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (TimmsJ1:ADPrincipal) [Add-ADGro upMember], ADIdentityNotFoundException
+ FullyQualifiedErrorId : SetADGroupMember.ValidateMembersParameter,Micros oft.ActiveDirectory.Management.Commands.AddADGroupMember
Add-ADGroupMember : Cannot find an object with identity: 'TimmsJ1' under:
'DC=rbbh-tr,DC=nhs,DC=uk'. At C:\Users\timmsj\Desktop\Scripts\User_Creation\RBFT_UC_Dev.ps1:169 char:1
+ Add-ADGroupMember -Identity $group2 -Members $SAMAccountName
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (TimmsJ1:ADPrincipal) [Add-ADGroupMember], ADIdentityNotFoundException
+ FullyQualifiedErrorId : SetADGroupMember.ValidateMembersParameter,Microsoft.ActiveDirectory.Management.Commands.AddADGroupMember
Please Wait Whilst We Find The AD Account & Create The Exchange Mailbox..
Enable-Mailbox : The operation couldn't be performed because object 'TimmsJ1' couldn't be found on 'rbhdc8red002.rbbh-tr.nhs.uk'.
At C:\Users\timmsj\Desktop\Scripts\User_Creation\RBFT_UC_Dev.ps1:175 char:1
+ Enable-Mailbox -Identity $SAMAccountName
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (0:Int32) [Enable-Mailbox], Manage mentObjectNotFoundException
+ FullyQualifiedErrorId : 637D7B43,Microsoft.Exchange.Management.Recipient Tasks.EnableMailbox
Username:
TimmsJ1
Password:
Welcome123
Email:
James.Timms1#royalberkshire.nhs.uk
Job Title - Department:
Test - Ultima
Home Directory:
\\RBHFILRED002\Users_05$\TimmsJ1
You will need to manually set the new user's group memberships. Please Do This
Before Sending The User's Account Details.
Press Any Key To Close

Answer 1

The parameter -Name sets not only the attribute name but also cn (common name), which must be unique just like sAMAccountName. To fix the issue change this:
$NewUserParams = #{
Path = "OU=Users,OU=RBFT,DC=rbbh-tr,DC=nhs,DC=uk"
SamAccountName = $SAMAccountName
Name = $DisplayName
DisplayName = $DisplayName
...
}
into this:
$NewUserParams = #{
Path = "OU=Users,OU=RBFT,DC=rbbh-tr,DC=nhs,DC=uk"
Name = $SAMAccountName
DisplayName = $DisplayName
...
}
When omitting -SamAccountName the value of the parameter -Name is automatically assinged as the sAMAccountName too.