Moving your law firm from on-premises to Microsoft 365? Don’t migrate without reading this first.

Why law firm cloud migrations fail more often than expected

The headline numbers look encouraging. Microsoft 365 migrations from on-premises Exchange have a 96% technical success rate when using Microsoft’s native tools with professional migration services. But technical and organizational success are not the same.

A migration can complete on time, on budget, and with all files in the right locations and still leave the firm worse off than before, because the content that moved was ungoverned, the lawyers couldn’t find what they needed, and the compliance team discovered that three years of policy review cycles had been missed.

The most common causes of post-migration dysfunction in law firms are:

• • Ungoverned content: documents with no named owner, outdated precedents sitting alongside current ones, duplicate versions across multiple site collections
• • Poor search continuity: lawyers who could navigate the old on-premises environment struggle to find equivalent content in the new structure
• • Compliance gaps: policies and procedures that weren’t reviewed before migration, now embedded in the new environment with their governance problems intact
• • User resistance: fee earners who find the new environment unfamiliar or harder to navigate than their old system, and revert to email and shared drives

The three things most firms don’t audit before they migrate

1. Outdated precedents

Most law firms have a significant volume of precedents that are out of date but still in use — because they’re the ones that appear in search results, and nobody has flagged them. When lawyers don’t trust the intranet, they email a partner instead — but when the intranet is migrated to a new environment, that informal workaround becomes even harder to sustain.

2. Orphaned document ownership

In a typical on-premises SharePoint environment that has been running for five or more years, a substantial proportion of documents have no current owner — because the person who created them has left, or because ownership was never formally assigned. These orphaned documents are a governance liability and a search quality problem. When they migrate to Microsoft 365, they bring those problems with them.

The migration is the right time to fix this. Requiring content ownership assignment as a pre-migration condition is one of the highest-value governance steps a firm can take — and it’s significantly easier to do with a tool that can identify and flag unowned content at scale.

3. Undocumented permissions

Law firms have complex, layered permission structures — matter-level access, practice-group restrictions, ethical walls, and partner-only content. In many on-premises environments, these permissions have evolved organically over the years and are no longer fully documented or understood by the current IT team.

Migrating undocumented permissions to Microsoft 365 is one of the riskiest things a law firm can do. Permissions that worked in the old environment may not translate correctly. Access that was restricted may inadvertently become open. Protected content may become visible to the wrong people.

How to use the migration as an opportunity, not just a move

The risk framing dominates most cloud migration discussions in legal. But for firms that approach it correctly, a migration to Microsoft 365 is actually a rare opportunity to fix years of accumulated governance problems that on-premises systems made too difficult to address.

Specifically:

• → A migration is an opportunity to establish a governed, searchable legal intranet that lawyers will actually use — rather than replicating the structure of the old environment in a new location
• → It’s an opportunity to consolidate multiple site collections, shared drives, and disconnected document libraries into a single, coherent information architecture
• → It’s an opportunity to implement automated content governance — review cycles, expiry notifications, ownership assignment — from day one in the new environment, rather than trying to retrofit it later
• → It’s an opportunity to integrate the DMS (iManage or NetDocuments) with the new Microsoft 365 intranet, creating a unified search experience that reduces toggle tax and improves lawyer productivity

What happens to iManage and NetDocuments during a Microsoft 365 migration

For firms running iManage or NetDocuments on-premises, the DMS migration is often a separate workstream from the intranet migration — but the two are deeply connected in terms of user experience.

iManage offers both on-premises and cloud deployment options. Firms migrating from iManage on-prem to iManage Cloud (or choosing to keep iManage on-prem while moving everything else to Microsoft 365) need to ensure that the intranet layer can connect to both configurations during and after the transition. A legal intranet that integrates with iManage regardless of deployment model means lawyers maintain consistent search access throughout the migration.

NetDocuments is cloud-native and therefore simpler to connect to a Microsoft 365 environment. But the same principle applies: the integration needs to be in place before migration completes, not as an afterthought once lawyers are already frustrated by the new environment.

A pre-migration checklist for law firms

Use this list as a starting point for migration planning:

• • Content audit: identify all documents with no named owner, last review date, or clear retention classification
• • Precedent library review: flag outdated precedents before they move to the new environment
• • Permissions documentation: map all existing access controls, ethical walls, and matter-level restrictions
• • DMS integration planning: confirm that iManage or NetDocuments will connect to the new intranet layer from day one
• • Intranet governance framework: establish content ownership rules, review cycles, and naming conventions before migration — not after
• • User readiness: build a structured communications and onboarding programme to guide lawyers through the new environment
• • Compliance continuity: confirm that audit trails, version history, and access logs will be maintained throughout the transition

Keeping lawyers productive during the transition

User resistance is the most common reason law firm technology projects underdeliver. Lawyers are busy, billing-focused, and deeply averse to workflow disruption. If the new environment is harder to use than the old one — even temporarily — they will find workarounds that undermine the entire migration.

The most effective mitigation is a well-configured legal intranet that gives lawyers a familiar, well-structured access point from day one of the new environment. Powell’s role-based content delivery, unified search, and low-code management tools mean that the new platform can be ready for lawyers before they even notice the infrastructure has changed.

Migrating to the cloud is a once-in-a-decade infrastructure decision. The firms that approach it as a governance opportunity — not just a technical move — are the ones that come out with a legal intranet that actually works, precedent libraries that can be trusted, and lawyers who spend less time searching and more time billing.

If you’re planning a cloud migration and want to understand how Powell can support the transition, talk to our team today.