Last Updated on December 23, 2025
A critical deadline is approaching for IT leaders. On July 14, 2026, extended support for SharePoint Server 2016 and 2019 will officially end. Once support expires, Microsoft will no longer issue security patches or updates, leaving on-premises environments exposed to increasing risks. For organizations still running these platforms, the moment has arrived to define a sustainable strategy for collaboration before legacy infrastructure begins to affect productivity and security.
SharePoint Online has emerged as the primary modernization route for many organizations. As part of Microsoft 365, it delivers enhanced security, modern collaboration tools, and integration across the broader Microsoft ecosystem. While SharePoint Server Subscription Edition remains a valid on-premises option, SharePoint Online offers the most compelling long-term value for most environments.
To support that journey, this article presents a three-step framework for planning a migration to SharePoint Online—helping you navigate the process with clarity, reduce risk, and align your transition with your organization’s future direction.
Three-Step Framework for a Smooth Transition
A successful migration begins with a thorough understanding of what you have. A comprehensive review is non-negotiable. It allows you to understand the full scope of your existing content, customizations, and functionalities. Many migration projects fail because teams underestimate the complexity hidden within their legacy environments. Don’t make that mistake.
Start by cataloging everything. You need to identify all sites and subsites, lists and libraries, and any active workflows. Pay special attention to custom code and third-party add-ons, as these often require special handling. Once you have a complete inventory, classify every asset. What needs to be migrated as-is? What must be rebuilt using modern tools? And, just as importantly, what can be retired or archived?
Your legacy SharePoint likely contains years of accumulated data. A significant portion of this is probably ROT—redundant, outdated, or trivial. Locating and removing this content before migration is a critical step. A thorough cleanup reduces the volume of data you need to move, which in turn lowers migration costs, shortens timelines, and simplifies the entire process.
Now, look at how your content is organized. Identify all existing content types, site columns, and other metadata structures. The goal is to map these classic elements to their modern equivalents in SharePoint Online. This is your chance to streamline your information architecture for better findability and governance in the new environment.
Classic SharePoint environments are often characterized by deep, hierarchical subsite structures. These rigid models are no longer the best practice. Instead, you should plan to modernize your architecture using a flatter structure built around hub sites. This approach provides more flexible navigation, consistent branding across related sites, and vastly improved search aggregation, making it easier for users to find what they need.
Finally, assess the complexity of your current permissions model. Over time, on-premises environments often accumulate a tangled web of custom permission levels, broken inheritance, and orphaned user accounts. These create significant security risks and management overhead. Use the audit to identify these issues and prepare a plan to simplify your model using modern security groups and proper inheritance in SharePoint Online. A clean permissions structure is essential to avoid post-migration access issues.
With a complete audit in hand, you can build a detailed roadmap for the migration itself. This plan will serve as your blueprint, guiding every decision from architecture to execution.
What are you trying to achieve? Document the key business drivers for the migration (beyond SharePoint end-of-life), whether it’s reducing infrastructure costs, improving collaboration, or enhancing security. From there, establish clear success criteria and the specific outcomes you expect. These goals will keep the project focused and provide a benchmark for measuring success.
Design what your new environment will look like. This involves planning the structure of modern Team Sites and Communication Sites and organizing them into a logical, hub-based architecture. It is also the time to establish clear governance policies for naming conventions, navigation patterns, and branding guidelines. Purposefully avoid recreating classic subsite models to ensure you get the full benefit of a modern architecture.
Your audit will have identified features that cannot be migrated directly. This includes old solutions like full-trust code, sandboxed solutions, classic publishing pages, and workflows built with SharePoint Designer. For each of these, you must plan a modern replacement or a complete rebuild.
SharePoint Online still has a 5,000-item view threshold for lists and libraries. To avoid performance issues, identify any large libraries and plan to restructure them. This can be achieved through a combination of creating indexed columns, using folders intelligently, and leveraging metadata-based filtering to manage large data sets effectively.
Many classic customizations have modern, cloud-native counterparts. Your plan should map these out clearly:
Document the technical specifications of your migration, including total storage size and item counts. Use your audit to flag any high-risk customizations or list view threshold violations that need to be addressed before you begin.
Several third-party tools can facilitate a SharePoint migration. Select a tool based on your project’s complexity, data volume, budget, and specific feature requirements, such as the ability to restructure content and map permissions during the move.
A phased migration is almost always preferable to a “big bang” approach. Break the project into manageable stages with clear milestones, such as assessment completion, a pilot migration, and go-live dates for different departments or phases. This allows you to test, validate, and iterate based on the results of your pilot, minimizing disruption. Always schedule final cutovers during low-usage periods to reduce the impact on business operations.
A technically perfect migration can still fail if users don’t adopt the new platform or if it becomes an ungoverned mess. This final step is about ensuring long-term success through people and policies.
Don’t underestimate the need for change management. Create targeted training materials, job aids, and host live sessions to get users comfortable with the new environment. Establish a network of champions or “super-users” who can provide peer support. Your change management strategy should be built on early communication, transparent timelines, accessible support resources, and clear feedback loops to address user concerns.
Prepare your support teams for the post-migration period. Create dedicated help desk workflows and clear escalation paths to address user issues promptly. Quick and effective support is crucial for building user confidence in the new platform.
Strong governance is the key to maintaining a healthy and secure SharePoint Online environment. Develop and enforce clear policies for site provisioning, naming conventions, permissions management, content lifecycle, and classification. A robust governance framework is essential for preventing data sprawl and oversharing. It also plays a critical role in ensuring high-quality, relevant results from tools like Microsoft Copilot, which rely on well-organized and properly permissioned content.
Leverage the native tools within Microsoft 365 to enforce your policies. This includes implementing sensitivity labels to protect confidential data, retention labels to manage the content lifecycle, and enabling auditing to track user activity. Configure other SharePoint governance settings to align with your organization’s compliance and security requirements.
Finally, ensure everyone understands their role in maintaining the environment. Clearly define responsibilities for key stakeholders:
Conclusion: Chart Your Path Forward With Confidence
The end-of-life for SharePoint Server 2016 and 2019 presents both a challenge and a significant modernization opportunity. It forces a necessary move away from aging infrastructure, but it also opens the door to a more powerful, secure, and integrated collaboration ecosystem in SharePoint Online.
By approaching the migration with strategic planning, you can convert this required upgrade into a true competitive advantage. A well-executed transition enhances productivity, strengthens security, and provides a platform for future innovation.
Expert guidance can help ensure your migration is a success—not just technically, but organizationally. Reduce risk and accelerate your path to a modern collaborative workplace with Microsoft Collaboration Services from MCPC. Our expertise in governance, architecture, and adoption ensures your teams can collaborate effectively from day one. Schedule a consultation to see how we can help you navigate your migration with confidence.