Mergers and acquisitions can look tidy on a spreadsheet and chaotic in real life. On day 1, you are not just combining 2 businesses. You are dealing with 2 sets of users, 2 ways of working, 2 security postures, 2 support models and, quite often, 2 very different expectations of what “good IT” looks like.
That gets even more complicated when offices, users and systems are spread across multiple countries.
If you want the deal to deliver value quickly, your IT integration plan needs to be practical, not theoretical. You need to protect the business, keep people productive and avoid turning the first 90 days into a stream of service desk tickets, access issues and security surprises.
That is where structured Global Support and International Projects become genuinely useful. Northern Star’s model is built around supporting offices in Europe, North America and Asia Pacific, with account management, remote help desk support and trusted local delivery wrapped around the same standards used at HQ.
Why IT support matters so much in M&A
A lot of integration risk sits inside the IT estate. User access, identity, device management, mail flow, shared files, security policies, licences, hardware standards and local support all affect whether the newly combined business feels joined up or stitched together.
There is also a clear security angle. The UK government’s Cyber Security Breaches Survey 2025 found that 43% of UK businesses identified a cyber breach or attack in the last 12 months. In an M&A setting, where systems, suppliers and permissions are changing quickly, that makes disciplined integration even more important.
The good news is that you do not need to solve everything on day 1. You just need a sensible sequence.
Days 1 to 30: Stabilise and get visibility
The first 30 days are about control. Not perfection. Your job is to make sure the combined business can function safely while you build a clearer picture of what you have inherited.
Start with people and access. You need a reliable view of who has access to what, where your admin privileges sit and whether any leavers, contractors or inherited accounts still have permissions they should not have. This is also the moment to review shared mailboxes, VPN access, MFA coverage and any local workarounds the acquired business has been relying on.
At the same time, map the core environment. That means users, devices, offices, networks, cloud platforms, business-critical applications, vendors and support contracts. If one side of the deal is running older infrastructure and the other is more cloud-led, you need that gap understood early so you can set priorities properly.
This is where a strong Consulting function helps. Northern Star’s approach centres on Technical Account Managers who stay close to your business, understand where you are trying to go and translate that into the right products, services and solutions.
You should also make sure user support is joined up from the start. If your teams in London, Frankfurt and New York all have different escalation routes and no one knows who owns what, frustration builds quickly. Northern Star’s IT Support and Management service is built around recognisable team members, customer-defined SLAs, 24/7 wraparound support and local response rather than anonymous call-centre handling.
In practical terms, your first 30 days should focus on:
Day 1 to 30 priorities
- set temporary governance for access, devices and change control
- audit users, permissions, domains and admin accounts
- identify critical systems and business dependencies
- review support coverage across all offices
- flag immediate cyber risks and unsupported systems
- decide what must stay separate for now and what can be aligned quickly
If cross-border data sharing is part of the integration, that needs careful handling too. The ICO says data sharing must be considered as part of due diligence in a merger or acquisition, including the original purpose for collecting the data and the lawful basis for sharing it after the transaction.
Days 31 to 60: Standardise the essentials
Once the immediate dust settles, the next 30 days are about reducing friction.
This is usually the point where you start aligning the basics: endpoint standards, collaboration tools, support processes, onboarding and offboarding, security controls, and reporting lines between local offices and the wider group IT function.
For many businesses, cloud platforms sit right at the centre of this phase. If you are trying to bring teams onto a common Microsoft 365 environment, rationalise tenants or move users to a more manageable setup, Cloud Services / Office 365 and Migrations (Platform to Platform) become central to the plan.
Northern Star positions both services around keeping users productive, reducing deployment costs and helping businesses move from older or fragmented systems to better-fit platforms.
This is also the right time to tighten your security baseline. The acquired business may not have the same controls, patching discipline or network protections as the acquiring side. Northern Star’s Security Services are built around proactive management, threat containment and protection against unauthorised access, while its Penetration Testing service is designed to expose vulnerabilities, prioritise risks and improve your defensive posture through ongoing assessment.
By the end of day 60, you should be aiming for fewer surprises, clearer ownership and a more consistent user experience.
Day 31 to 60 priorities
- Align identity and access policies
- Standardise collaboration and communication tools
- Review licence overlap and wasted spend
- Set common support workflows and escalation paths
- Strengthen endpoint, network and account security
- Plan any urgent tenant, mailbox or data migrations
If you have acquired offices across Europe, European IT support can be particularly useful here because local support quality often makes the difference between a neat integration plan on paper and one that actually works on the ground. Northern Star specifically positions this service around integrating into your procedures and operational infrastructure while supporting users across London, the UK and the rest of Europe.
Days 61 to 90: Optimise and build for the long term
By this stage, you should be moving away from reactive problem-solving and into a more deliberate operating model.
This is where you start making longer-term decisions about platform consolidation, local office support structure, supplier rationalisation, hardware refreshes and whether some systems should be retired altogether. If inherited devices or legacy kit are slowing users down, a review of Hardware and Software standards can help bring consistency back into the environment.
You should also formalise governance. Who owns security? Who signs off changes? How are overseas offices represented? How often are service reviews happening? Northern Star’s wider Why Us story is built around its account management methodology, embedded services, proven quality support and 24/7 support model, which fits well with post-deal environments that need continuity rather than constant handoffs.
This is also the point where culture starts to matter more. Good M&A support is not only about technology. It is about giving staff confidence that they know where to go for help, who is responsible and what the future model looks like. A visible, credible support team makes that much easier, especially when you are dealing with multiple offices and time zones. Northern Star’s team and broader business support approach help reinforce that message of local support with global reach.
Day 61 to 90 priorities
- Complete the roadmap for strategic migrations
- Rationalise vendors, contracts and overlapping tools
- Improve reporting, SLAs and service reviews
- Refresh weak hardware and unsupported software
- Embed security testing and ongoing risk reviews
- Define the long-term global support model
Keep the plan practical
The mistake many businesses make is trying to force full integration too quickly. The smarter move is to stabilise first, standardise second and optimise third.
That gives you room to protect service quality, avoid unnecessary disruption and make better decisions about where to invest. It also helps you keep control of cost. In M&A, IT overspend often comes from duplication, rushed migrations and emergency fixes, not just from the headline technology budget.
If you want your merger or acquisition to feel joined up across offices, teams and time zones, the first 90 days matter more than almost anything that comes after.
If you need help building a realistic integration plan, speak to Northern Star about global support, migration planning and secure post-deal IT delivery. You can also explore their services, read more in Latest News, or see how their global support model can help you keep every office productive from day 1.
