Best Practice Guide: Microsoft 365 Tenant-to-Tenant Migrations

Updated January 19, 2026 14:52

This guide, based on CloudM's Recommended Migration Strategy, provides a comprehensive workflow and best practices for performing a Microsoft 365 tenant-to-tenant migration. It addresses the complexities of migrating all supported entities and ensures minimal disruption.

Prerequisites and Initial Setup

This foundational stage is critical for preparing your environments before any data is moved.

1. Licensing & Connections

Licensing: It is recommended to purchase CloudM Migrate licensing for the destination's default onmicrosoft.com domain. Product Improvement: Licenses are tracked by ID; renaming users or updating addresses in the Items to migrate list does not consume extra seats.
Connection Setup: Configure your source and destination Microsoft 365 connections using the default onmicrosoft.com domain in the Domain Name field for both. This ensures the connection remains stable even when vanity domains are removed or added.
Detailed Guides: Source Setup | Destination Setup

2. Limited Scopes (Best Practice)

For enhanced security, you can configure your connections to use limited scopes, restricting permissions to only what is necessary.

3. Initial Batch Configuration

We recommend creating a dedicated migration batch for each entity type (Users, Shared Mailboxes, SharePoint, Groups). Creating a separate batch for Teams is essential due to its unique configuration and required multi-pass approach.

4. User and Entity Creation

Admin Username: This must be a Global Admin account. If migrating Teams/Groups, this account must also have a valid M365 license that includes Teams.
Destination Readiness: Create users manually or via PowerShell to ensure licensing and OneDrive are correctly provisioned.
Link: Pre-provision OneDrive for users

Initial Migration (Phase 1)

This stage handles the initial bulk migration of historical data, often using date range filters to capture older content first.

Phase 1A: Mail & File Migration

Entities: Users, Shared Mailboxes, Microsoft 365 Groups, SharePoint Team Sites.
Items: Mail and Drive.

Phase 1B: Microsoft Teams Initial / Bulk Migration

Entities: Microsoft Teams.
Items: Mail, Conversations, and Drive.
Configuration: Enable Configuration > Source > Microsoft Teams/Groups > Teams Direct Migration.

Delta Migration (Phase 2)

This stage captures recent changes since the bulk migration and finalizes all data.

Phase 2A: Users, Groups, and SharePoint

Items: ALL item types.
Teams Chat API: If migrating private chats, you must specify a payment model (Model A or B).
Reference: Configuration > Source > Microsoft Teams/Groups > Teams chat API licensing model

Phase 2B: Microsoft Teams Finalization

This phase finalizes the Teams environment with post-migration changes, including tabs and Planner data.

Configuration:
- Enable Teams Direct Migration and Finalize Teams Direct Migration.
- Enable Migrate Teams Channel Tabs and Migrate Teams Planner.
Action: Conduct a delta migration for Teams to update content, tabs, and Planner data.

Phase 3 (Optional): Private Channel Migration

Handles Private Channels which cannot be migrated in 'Direct Migration' mode. This must be a single run after all other phases are complete.

Configuration: Disable Teams Direct Migration and all related settings.
Items: Select only Drive and Conversations. (Shared file data for Private Channels is subject to 100GB licensing increments).

Per-Entity Migration Guides