-
Written By
Simran Bhatia -
Approved By
Sonika Rawat -
Updated on
August 22nd, 2026 -
Read Time
9 minutes
Due Diligence Checklist IT Leaders Need Before M&A Migration
Introduction: While a merger or an acquisition can be made by the company as part of its business strategy. It can prove to be very demanding for the IT department. Both businesses may use different tenants of Microsoft 365, user identities, security configurations, SaaS applications, data stores, and backup solutions. If merged without verification beforehand, this may lead to unexpected security and data issues and delays in the migration process.
This is where M&A IT due diligence becomes important. It helps IT teams review the existing technology, find possible risks, identify unnecessary systems or data, and decide what needs to be moved or changed. Ideally, this review should begin before the migration and, when possible, before the deal is finalized. In this guide, we will cover the key areas of IT due diligence and explain how to prepare for a Microsoft 365 tenant-to-tenant migration.
What Does IT Due Diligence for Mergers and Acquisitions Mean?
IT due diligence is simply the process of reviewing a company’s entire technology setup before a merger or acquisition closes. That means looking at infrastructure, cloud platforms, identity systems, security posture, compliance obligations, data quality, and every application in use. So both sides know what integration will actually take, not just what it’s supposed to take on paper.
Why Is M&A IT Due Diligence Important?
An acquisition can bring much more than employees and business operations. It can also bring cloud tenants, applications, databases, identities, storage systems, security policies, contracts, and years of business data. If these systems are moved without proper assessment, the company may face:
- Unexpected migration costs
- Security gaps
- Duplicate applications
- Conflicting user accounts
- Compliance problems
- Data loss or duplication
- Legacy system dependencies
- Unplanned downtime
- Migration delays
The goal of M&A technology due diligence is not simply to create an inventory. It is to understand how the technology environments fit together and what needs to happen next. According to the reference checklist, conducting due diligence before an M&A migration helps IT teams identify technical, security, and compliance risks early and create a more practical integration strategy.
M&A Migration Checklist
- Create an IT Asset Inventory: Start by documenting what each company currently uses. The inventory should include:
- Microsoft 365 or Google Workspace tenants
- Exchange Online mailboxes
- OneDrive and SharePoint data
- Google Drive and Shared Drives
- Microsoft Teams or Slack
- Active Directory and Microsoft Entra ID
- SaaS applications
- Databases
- Cloud infrastructure
- Backup systems
- Business-critical applications
- Review Identity and Access Management: Identity problems are common during M&A because two companies usually have separate directories and different account structures. Review:
- Microsoft Entra ID
- Active Directory
- User accounts
- Administrator accounts
- Groups
- Guest users
- External users
- Single sign-on
- Multi-factor authentication
- Conditional Access policies
- User permissions
- Check Cybersecurity: An M&A can introduce security risks that were not visible before the acquisition. Review the target company’s:
- Security policies
- Endpoint protection
- Email security
- MFA configuration
- Conditional Access
- Data Loss Prevention policies
- Encryption
- Vulnerability reports
- Security incidents
- Audit logs
- Review Compliance and Legal Requirements: Depending on the business, review requirements related to:
- GDPR
- HIPAA
- ISO 27001
- SOC 2
- PCI DSS
- Data retention
- Legal holds
- eDiscovery
- Audit logging
- Data residency
- Assess Data Quality: Do not migrate everything just because it exists. Old and unnecessary data can increase migration time, storage requirements, and administrative work. Before migration, identify:
- Duplicate files
- Old documents
- Inactive mailboxes
- Large file repositories
- Orphaned accounts
- Unused SharePoint sites
- Broken permissions
- Redundant data
- Review SaaS Applications and Licenses: M&A often results in duplicate software. Both organizations may be using different tools for the same purpose. For example, one company may use one project management platform while the other uses another. Create a list of:
- SaaS applications
- Active licenses
- Expiring licenses
- Business-critical applications
- Application owners
- Integrations
- Shadow IT applications
- Unused subscriptions
- Check Microsoft 365 Migration Readiness: If the M&A involves Microsoft 365, perform a detailed tenant assessment before starting the migration. Check:
- Number of users
- Mailbox sizes
- Shared mailboxes
- Distribution lists
- Microsoft 365 Groups
- OneDrive data
- SharePoint sites
- Teams data
- User permissions
- Domains
- UPNs
- SMTP addresses
- Existing licenses
- Security policies
- API requirements
- Migration dependencies
- Review Backup and Disaster Recovery: Never begin a large M&A migration without understanding the existing backup situation. Check:
- Backup frequency
- Backup retention
- Recovery Point Objective (RPO)
- Recovery Time Objective (RTO)
- Disaster recovery procedures
- Backup locations
- Restoration procedures
- Last successful restore test
- Identify Legacy Systems and Technical Debt: Older systems can become hidden migration blockers. Look for:
- Unsupported operating systems
- End-of-life software
- Old authentication methods
- Custom applications
- Manual workflows
- Legacy databases
- Outdated servers
- Applications with no current owner
- Build the M&A Migration Roadmap: Once the assessment is complete, create a migration roadmap. The roadmap should define:
- Which workloads will move
- Which systems will remain
- Applications that will be retired
- Migration priorities
- Pilot users
- Migration waves
- Data validation
- User communication
- Cutover date
- Rollback plan
- Success criteria
How Does M&A IT Due Diligence Help Microsoft 365 Tenant Migration?
Due diligence and migration are two different stages of the same project. Due diligence answers: “What do we have, what are the risks, and what needs to change?” Migration planning answers: “How will we move the required data and users?”
For example, suppose Company A acquires Company B. Company A already has 2,000 Microsoft 365 users, while Company B has 300 users. Both companies have separate tenants. During due diligence, the IT team discovers that Company B has:
- 300 Exchange Online mailboxes
- SharePoint sites
- OneDrive accounts
- Shared mailboxes
- Duplicate user accounts
- Several inactive accounts
The team can then remove unnecessary accounts, identify the data that must be retained, map users, and plan the migration in waves. This is much safer than starting the tenant migration without understanding the source environment.
Use Microsoft 365 Tenant to Tenant Migration Tool After Due Diligence
SysInfo Cross-Tenant Migration is a hassle-free tool that lets users migrate Mailbox, SharePoint, OneDrive, and Teams data without data loss. It uses Modern Authentication or Admin Impersonation for 100% secure authentication. This tool also allows users to perform Mailbox, SharePoint, or OneDrive deduplication. Date Filter, Remove Duplicates, Bulk Migration, and several other features. Incremental migration is also performed.
Quick Reference to Migrate Tenant to Tenant Before M&A IT Due Diligence
|
Steps |
Description |
|
Select Source |
Run the software and choose Mailbox, SharePoint, OneDrive, or Teams. |
|
Source or Destination Authentication |
Enter your source or destination tenant credentials to authenticate. |
|
Mapping, Features, & Start Export. |
Use mapping, apply features, and filters. Press Start Export. |
Note: For detailed steps, check the software guide for SysInfo Microsoft 365 Tenant to Tenant Migration Tool.
Merger and Acquisition IT due diligence Best Practices
- Start IT due diligence early.
- Build a complete technology inventory.
- Involve security, compliance, infrastructure, and application teams.
- Review identities and permissions carefully.
- Remove unnecessary data before migration.
- Identify duplicate applications and licenses.
- Check backup and recovery procedures.
- Test the migration with a pilot group.
- Use migration waves instead of one large cutover where practical.
- Validate data after every migration phase.
- Document the rollback process.
- Communicate migration plans to users.
Final Words
M&A IT due diligence provides insight into the technological environment of organizations prior to beginning the process of migration. Assessing users, security, data, applications, compliance, and backups in advance can avoid possible issues that can lead to high costs in the future. It is also important to have an appropriate migration plan for mergers in Microsoft 365. Once the process of assessment is completed, the migration tool can be used to transfer the necessary data in a structured manner.
Frequently Asked Questions
Q1. Why is IT due diligence necessary for mergers and acquisitions?
Ans. IT due diligence helps to detect any IT-related problems before they have an effect on the integration process. IT due diligence also helps to understand what effort and money are needed for the integration.
Q2. How do you perform IT due diligence for mergers and acquisitions?
Ans. Start by reviewing the IT assets of both companies. Check cloud platforms, users, applications, security controls, data, licenses, compliance requirements, backups, and legacy systems. The findings can then be used to prepare the integration plan.
Q3. What steps will you take to evaluate cloud infrastructure during IT due diligence during M&As?
Ans. Consider cloud infrastructure, tenants, users, storage, workloads, security configurations, access, volume of data, and current dependencies. This would help in determining what can be consolidated, decommissioned, or kept.
Q4. How does an organization identify technical debt in M&A due diligence?
Ans. Look for obsolete software, unsupported systems, old servers, legacy applications, manual processes, and obsolete forms of authentication. Every system needs to be audited to determine whether it should be migrated, upgraded, or even phased out.
Q5. How do I create an IT migration plan for a merger or acquisition?
Ans. First, identify the systems and data that need to move. Then prepare user mapping, set migration priorities, select pilot users, plan migration waves, define a cutover schedule, and keep a rollback plan ready.
Q6. What type of security testing needs to be conducted when undertaking IT Due Diligence for mergers and acquisitions?
Ans. Test MFA, admin accounts, permissions, CA, endpoint protection, email security, encryption, DLP policies, vulnerabilities, log auditing, and past security incidents.
Q7. What is the method IT staff can employ to avoid disturbances during post-merger integration?
Ans. Apply the approach of phased migration rather than doing it all at once. Pilot, test, migrate the users in phases, communicate well, and validate the migrated data after every phase.
Q8. How can an M&A IT due diligence checklist reduce migration risks?
Ans. A checklist helps IT teams review important areas before migration and reduces the chance of missing critical dependencies. It can reveal security gaps, duplicate data, identity issues, legacy systems, and other problems early.
About The Author:
Simran Bhatia is a technical content writer engaged in writing clear, concise, and SEO-optimized content. With a background in computer science and a passion for writing, I thrive to deliver complex technical content in simple layman terms.
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