Effective IT Solutions for Seamless Post-Merger Integration
When companies acquire new subsidiaries, a complex so-called Post Merger Integration begins – not only culturally but especially technically. While the next growth step is already being planned on a strategic level, the IT situation often looks quite different: Two directories (if not more), two governance models, duplicate users, duplicate licenses – and no unified control.
Integration then fails not because of intent but due to manual processes, licensing chaos, and lack of transparency. Especially in Microsoft-centric environments with Active Directory, Microsoft 365, and Entra ID, classic integration strategies quickly reach their limits.
Index
Why Post Merger Integrations often fail in IT
Different systems, rules, and security requirements need to be merged – which is particularly challenging with international subsidiaries.
What sounds like centralized control strategically often fails in practice due to technical challenges: systems don’t fit together, processes are not aligned, and security concerns slow progress. Costs must also be considered.
In the end, each unit continues to work on its own – which comes at the expense of efficiency, security, and user-friendliness.
Typical symptoms in companies with distributed identity systems:
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Licensing is expensive and complicated – especially when separate licenses are needed for external users such as partners.
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Duplicate and incomplete identities – employees working across multiple units get multiple accounts – often without clean assignment.
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Lack of timely access – employees wait for permissions because central processes are missing or too slow.
These problems add up to enormous administrative effort – not to mention security risks and frustration among end users.
Three common approaches and their weaknesses
Many companies try to connect new units through one of the following methods:
- full license assignments
- guest accounts
- isolated local IT structures
- The first option leads to overprovisioned Microsoft 365 tenants, high costs, and complicated rights management.
- The second option, guest usage via Entra ID B2B, reduces license needs but complicates role management and lacks central governance mechanisms.
- The third option, leaving local IT structures untouched, delays data exchange, complicates central management, and opens the door to security gaps.
⏹️ None of these solutions meets the requirements of modern post-merger integration. Dynamic group membership also reaches technical limits with massive attribute changes. Rule processing in Entra ID does not happen in real time and may take several hours under heavy load, a critical aspect in large-scale acquisitions.
Many IT departments struggle with complicated structures, duplicate identities, and too many manual tasks. To change this, a new, well-thought-out approach is needed – one that is simple, secure, and easy to control.
What is needed for a Post Merger Integration
To manage identities well today, a new approach is needed. The solution is not more rules or more control but a system that is flexible, secure, and easy to manage.
- Roles instead of individual permissions
Instead of assigning rights individually to each person, it is better to work with roles. A role bundles typical tasks and accesses – for example, “Marketing Employee” or “External Project Manager.” This makes management simpler and clearer. - Multi-tenant support
Many companies today work with multiple organizations, subsidiaries, or partners. The system must support multiple environments (tenants) – for example, different Microsoft Entra ID instances. Identity management must not stop at a boundary. - Dynamic management
Some things change frequently – such as department, location, or project. A good system automatically recognizes these changes and adjusts group memberships or accesses accordingly. This keeps everything up to date without manual intervention. - Delegation instead of centralization
Not everything needs to be regulated by central IT. It is often better to distribute tasks: to departments, project managers, or external partners. Identities are maintained where they originate. This saves time, avoids errors – and IT still keeps oversight. - Clear group logic for dynamic and hybrid environments
Group structure is crucial for reliably implementing access rights. In hybrid Microsoft environments with Active Directory and Entra ID, classic security groups, Microsoft 365 groups, and dynamic groups must be combined sensibly.
Dynamic security groups enable automatic membership based on attributes like department or location – provided Entra ID P1 is in use. This smart management is important to create order and transparency – especially in complex IT landscapes.
With this new approach, identity management becomes simpler, faster, and more secure – and companies are better prepared for the future.
The role of the my-IAM platform in company acquisitions
my-IAM manages distributed identities
A large company with several thousand employees usually grows through acquisitions. New companies mean new employees – and all should be quickly integrated into the existing IT environment and able to work immediately.
The my-IAM platform service RealIdentity by FirstAttribute helps to seamlessly integrate new entities. It doesn’t matter whether employees are already guests or B2B members in the company’s tenant or if they have only been managed locally in the AD or Entra ID of the subsidiary so far.
➡️ RealIdentity brings all identities to a uniform level, cleans up duplicates, and updates the central directories.
This creates a unified, up-to-date identity profile. New employees can work directly in Outlook, Teams, SharePoint, or specialized applications – without long wait times or manual follow-up. At the same time, subsidiary identities are checked, sorted, and automatically assigned to groups or roles for immediate rights assignment.
IDM-Portal for Post-Merger User Management
New systems and structures often cause the number of users to manage to grow rapidly. For IT, this is a time-consuming, daily challenge.
✅ A helpful solution is to delegate standard tasks.
With a user-friendly IAM solution, for example, managers or HR employees of the new subsidiary can take action themselves. They maintain user data or initiate access requests — without detours through IT. This saves time and noticeably relieves the IT department.
The IDM-Portal — an Identity and Access Management solution from FirstAttribute — makes exactly this possible. It is easily accessible via the web for authorized persons, no matter their location or which system they work in.
Users can view all important identity and group information and, if needed, update it themselves. In the background, RealIdentity reviews these changes and securely and correctly transfers them to the respective target systems — both within the parent company and subsidiaries.
The results speak for themselves:
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New companies become operational faster
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Access and licenses are assigned cleanly
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IT departments maintain control
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Business units can collaborate independently
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The platform grows with the organization — also in hybrid or multi-tenant environments
Conclusion: Post-Merger Integration with structure instead of chaos
When companies grow and integrate new subsidiaries, IT departments face a major challenge:
Different systems, duplicate identities, and high manual effort lead to license chaos, security risks, and lack of transparency. Traditional integration approaches — such as guest usage or full license assignment — quickly reach their limits in Microsoft-centric environments.
What is needed is a future-proof approach:
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Role-based management instead of individual permissions
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Multi-tenant capability for hybrid IT landscapes
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Automated group management
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Delegation to business units without loss of control
The my-IAM platform delivers exactly this approach — including automatic duplicate checking, cross-system synchronization, and dynamic group logic. This way, new employees can start quickly, securely, and without extra effort in Microsoft Teams, Outlook, or SharePoint.
Would you like to relieve your post-merger IT and integrate new companies securely?
Together with you, we develop a tailored solution — individually customizable, secure, and proven in practice.
More about the my-IAM platform
The my-IAM platform unites all identities from various source systems and makes them usable for applications and apps of all kinds. Besides the Teams-integrated app my-IAM PeopleConnect, it includes the business services my-IAM RealIdentity and my-IAM RealGroup.
You can also reach our team by phone at
+49 8196 998 4330
