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TEAMS.TC.5008 - Anonymous users should not dial out

Anonymous users should not be allowed to dial out​

Description​

This test checks if anonymous users are restricted from dialing out from Microsoft Teams meetings.

Policy Statement​

Contoso's company policy requires that anonymous users should not be allowed to dial out from meetings to prevent toll fraud and unauthorized PSTN usage. Allowing anonymous dial-out creates potential for abuse and unexpected communication charges.

Why This Matters​

Security and Financial Risks:

When anonymous dial-out is enabled:

  • Potential for toll fraud and unauthorized charges
  • Risk of PSTN resource abuse
  • Difficulty tracking call accountability
  • Unexpected communication costs
  • Potential for international calling abuse
Financial Risk

Anonymous dial-out can lead to toll fraud where unauthorized users make expensive phone calls at your organization's expense, potentially resulting in thousands of dollars in fraudulent charges.

Availability

This setting may not be available in all licensing tiers or tenant configurations. The test will be skipped if the property is not available in your tenant.

How to fix​

Disable Anonymous Dial Out in Teams Admin Center​

  1. Navigate to the Teams admin center - Meeting policies
  2. Select the Global (Org-wide default) policy
  3. Under Participants & guests, locate Let anonymous people dial out to phone numbers
  4. Set this option to Off
  5. Click Save

Verify via PowerShell​

# Connect to Teams
Connect-MicrosoftTeams

# Check if the property exists and current setting
$policy = Get-CsTeamsMeetingPolicy -Identity Global
if ($policy.PSObject.Properties['AllowAnonymousUsersToDialOut']) {
    $policy | Select-Object AllowAnonymousUsersToDialOut
} else {
    Write-Host "AllowAnonymousUsersToDialOut property not available in this tenant"
}

# Disable anonymous dial out (if property exists)
Set-CsTeamsMeetingPolicy -Identity Global -AllowAnonymousUsersToDialOut $false

# Verify the change
Get-CsTeamsMeetingPolicy -Identity Global | Select-Object AllowAnonymousUsersToDialOut

Impact​

Disabling anonymous dial out will:

  • ✅ Prevent toll fraud from anonymous users
  • ✅ Reduce unauthorized PSTN charges
  • ✅ Improve accountability for dial-out usage
  • ⚠️ Anonymous users cannot dial phone numbers from meetings
info

Only authenticated users will be able to dial out to phone numbers from Teams meetings, ensuring accountability and reducing fraud risk.