How to Configure Information Barriers, Ethical Walls, and Communication Compliance in Teams

In global financial institutions, healthcare networks, corporate legal firms, and national government defence agencies, preventing insider trading, conflicts of interest, and regulatory breaches is a strict legal requirement. Regulatory bodies such as the UK Financial Conduct Authority (FCA), the US Securities and Exchange Commission (SEC), and FINRA mandate strict “Ethical Walls” between competing departments—such as isolating investment banking analysts advising on corporate acquisitions from public equity research traders. Without technical safeguards, accidental chat messages or shared team channels can trigger multi-million-pound compliance fines.

Microsoft addresses these regulatory demands by integrating Information Barriers (IB) and Communication Compliance across Microsoft Teams and Microsoft 365 through the Microsoft Purview governance ecosystem. By defining dynamic user segments and deploying bidirectional barrier policies, Purview prevents prohibited user groups from communicating via 1:1 chat, initiating voice calls, joining shared meetings, or co-authoring files within Microsoft Teams channels.

Architectural Overview: The Purview Information Barrier Subsystem

Information Barriers operate across the Microsoft Teams transport layer and Microsoft Graph Directory substrate:

Layer	Technical Architecture	Enforcement Behaviour in Microsoft Teams
User Segments	Entra ID Attribute-Based Filtering	Groups users dynamically based on directory attributes (e.g. Department, Division, Location).
IB Policies (v2)	Purview Compliance Policy Engine	Evaluates communication requests in real time; supports multi-segment user assignments.
Teams Chat & Calling	Transport-Level Barrier Gateways	Blocks 1:1 chats, removes restricted users from group chats, and rejects voice/video calls with immediate policy alerts.
SharePoint & OneDrive	Connected Group Site Confinement	Locks connected Team document libraries, preventing unauthorized file sharing across isolated segments.

Prerequisites and Entra ID Directory Hygiene

Information Barrier policies rely entirely on accurate metadata populated within Microsoft Entra ID (formerly Azure Active Directory). Before defining policies, ensure directory attributes are consistently assigned.

Step 1: Audit User Directory Attributes

Ensure all employees within regulated units possess distinct attribute values (for instance, Department = "Investment Banking" and Department = "Equity Research").

Step 2: Enable Information Barriers in Microsoft Teams

Enable tenant-wide Information Barrier enforcement in the Microsoft Teams admin centre or via PowerShell:

# Connect to Microsoft Teams PowerShell
Connect-MicrosoftTeams

# Verify tenant-wide IB mode
Set-CsTeamsClientConfiguration -EnableInformationBarriers $true

Defining User Segments in Microsoft Purview PowerShell

Information Barrier policies are engineered using the Exchange Online / Security & Compliance PowerShell module.

Step 1: Establish PowerShell Session

# Connect to Security & Compliance PowerShell
Import-Module ExchangeOnlineManagement
Connect-IPPSSession -UserPrincipalName [email protected]

Step 2: Create Organization Segments

Define two mutually exclusive operational segments based on Entra ID directory filters:

# Segment 1: Investment Banking Division
New-OrganizationSegment -Name "Segment-InvestmentBanking" -UserGroupFilter "Department -eq 'Investment Banking'"

# Segment 2: Equity Research Analysts
New-OrganizationSegment -Name "Segment-EquityResearch" -UserGroupFilter "Department -eq 'Equity Research'"

# Segment 3: General Human Resources & Corporate IT (Neutral Segment)
New-OrganizationSegment -Name "Segment-Corporate" -UserGroupFilter "Department -eq 'Corporate'"

Authoring and Activating Information Barrier Policies

Once segments are established, create barrier policies declaring which segments are prohibited from communicating.

Step 1: Create the Bidirectional Block Policies

# Block Investment Banking from communicating with Equity Research
New-InformationBarrierPolicy -Name "Policy-IB-Blocks-Research" -AssignedSegment "Segment-InvestmentBanking" -SegmentsBlocked "Segment-EquityResearch" -State Active

# Mirror policy: Block Equity Research from communicating with Investment Banking
New-InformationBarrierPolicy -Name "Policy-Research-Blocks-IB" -AssignedSegment "Segment-EquityResearch" -SegmentsBlocked "Segment-InvestmentBanking" -State Active

Step 2: Trigger Policy Evaluation Across the Tenant

Information Barrier policies do not apply instantly; they must be compiled into the Microsoft Graph security directory:

# Initiate tenant-wide background policy application
Start-InformationBarrierPoliciesApplication

Monitor the provisioning status using:

Get-InformationBarrierPoliciesApplicationStatus

Depending on the total tenant seat count (from 1,000 to 100,000 users), processing completes within 1 to 4 hours.

Enforcement Behavior: What End Users Experience in Microsoft Teams

Once policies reach the Completed state, Microsoft Teams enforces ethical walls automatically:

• 1:1 Chat Lookup: When an Investment Banker searches for an Equity Researcher in Teams chat, the recipient is either invisible or displays: “You can’t message this person because your organization’s policies restrict communication.”
• Group Chat Partitioning: If an unregulated user attempts to add an Investment Banker and an Equity Researcher to the same group chat, Teams blocks the addition.
• Meetings & Calls: Direct voice/video calling is barred. In scheduled group meetings, the prohibited attendee is ejected or restricted to lobby hold.
• Team & Channel Membership: Teams automatically sweeps existing team channels: if a restricted user exists in a channel containing members of the opposing segment, the user is removed and their file access revoked.

Configuring Communication Compliance for Proactive Monitoring

While Information Barriers block communication pathways, Purview Communication Compliance analyzes permitted communications for illicit keywords, insider trading discussions, or harassment.

1. Navigate to the Microsoft Purview Compliance portal (compliance.microsoft.com).
2. In the left sidebar, click Communication compliance.
3. Click Policies > Create policy > Detect regulatory compliance violations.
4. Define supervising scopes:
   • Supervised Users: Select the Investment Banking and Research segments.
   • Communication Channels: Check Teams chats, Teams channels, and Exchange Online emails.
   • Conditions & Lexicons: Select pre-built financial dictionaries (e.g. Regulatory Financial Terms, Confidential Info, or custom stock ticker keywords).
   • Reviewers: Designate the Corporate Legal and Compliance audit team.
5. Click Finish to engage continuous machine-learning supervision.

Troubleshooting Information Barrier Policies in Microsoft Teams

Consult this diagnostic reference table to debug policy conflicts and synchronization lag:

Issue	Underlying Root Cause	Remediation Procedure
Policy application stuck in NotStarted or InProgress status.	Another policy application cycle is currently executing, or Directory Synchronization (DirSync) is reconciling Entra ID changes.	Allow the active application job to conclude. Check status via Get-InformationBarrierPoliciesApplicationStatus before submitting fresh jobs.
Users in isolated segments can still send chats to each other.	The Teams desktop client has cached older security tokens, or user attributes in Entra ID do not match the UserGroupFilter.	Verify user attributes via Get-Recipient [email protected]. Instruct users to sign out and restart the Teams desktop client to flush client-side token caches.
Legitimate collaborative team channel members were unexpectedly removed.	The Team contains members from conflicting segments; Information Barriers automatically sweeps and removes conflicting accounts.	Segment channels into distinct private teams, or assign shared external guest accounts that exist outside regulated internal segments.
Error: Segment assignment overlap detected.	In legacy IB v1, a user matched more than one segment filter.	Ensure user attributes are mutually exclusive, or upgrade the tenant to Information Barriers v2 which natively supports multi-segment user assignments.

Deploying Information Barriers and Communication Compliance inside Microsoft Teams transforms enterprise communications into a compliant, audit-ready environment, isolating sensitive business units and safeguarding organizations against catastrophic regulatory non-compliance.