Introduction:

Microsoft 365 has become an indispensable tool for organizations around the world. It provides a range of features and services that help businesses improve their productivity and collaboration. However, in recent trends, companies worldwide are growing rapidly and also, mergers and acquisitions are on the rise. On such occasions, the companies find the need to migrate their Microsoft 365 tenant to another one. This can be a challenging and time-consuming process, but with the right planning and execution, it can be completed successfully. In this article, you will find a step-by-step guide on how to migrate Microsoft 365 from one tenant to another tenant.

Step 1: Planning

The first step in any migration process is to plan. Planning is a crucial aspect of any migration, and it is no different when it comes to tenant-to-tenant migration. It is essential to create a migration plan that outlines the entire process, including the timeline, the data to be migrated, and any potential issues that may arise. Additionally, it is vital to communicate the migration plan with all stakeholders involved, such as IT teams, end-users, and third-party vendors. Before starting the migration, it is essential to have a clear understanding of your current Microsoft 365 tenant environment and the new one. Here are some questions that help you decide on framing your plan:

• What data needs to be migrated?
• What is the current size of your Microsoft 365 tenant?
• What are the limitations of your new Microsoft 365 tenant?
• What is the expected downtime during the migration process?
• What are the technical requirements for the migration?

Once you have answered these questions, you can begin to develop a migration plan. 

The plan should include the following:

• Timeline: A detailed timeline that outlines the migration process from start to finish.
• Communication: A plan for communicating with stakeholders, including employees, customers, and vendors, about the migration process.
• Testing: A plan for testing the migration process before it goes live.
• Rollback plan: A plan for reversing the migration if something goes wrong.

Step 2: Preparation

Before starting the migration process, it is essential to understand your tenant environment and prepare the source and target tenants. This includes verifying the source tenant's data, such as user accounts, groups, and permissions. Also ensure that there are no conflicts with the data in the target tenant. Additionally, it is vital to prepare a backup plan in case something goes wrong during the migration process.

This involves the following steps:

• Backup: Backup all your data and settings from the source Microsoft 365 tenant.
• License: Purchase the necessary licenses for your new Microsoft 365 tenant.
• Verification: Verify the domain names in the new tenant and create the necessary accounts and security groups.
• Network: Set up the network connectivity between the source and destination Microsoft 365 tenants.

Step 3: Migration

Once you have completed the planning and preparation, you can begin the migration process. It is essential to test the migration process in a non-production environment before performing the actual migration. This will help to identify any potential issues and ensure that the migration process runs smoothly.

Follow these steps to perform migration:

• Use a third-party migration tool: You can use a third-party migration tool to move your data from the source tenant to the destination tenant. These tools offer a range of features that make the migration process faster and easier.
• Migrate mailbox data: Start with migrating mailbox data, which includes emails, contacts, calendars, and tasks. You can migrate mailbox data either in batches or all at once, depending on your needs.
• Migrate SharePoint and OneDrive data: Next, migrate your SharePoint and OneDrive data. This includes documents, images, and videos.
• Migrate other data: Finally, migrate any other data that needs to be moved, such as Teams, Planner, and Power BI.

Step 4: Post-Migration

Once the migration is complete, you need to verify that all the data has been migrated correctly. This also includes updating any necessary configurations, and ensuring that end-users can access their data in the target tenant. 

Here are the steps to follow:

• Verify mailbox data: Check that all mailbox data has been migrated correctly, including emails, contacts, calendars, and tasks.
• Verify SharePoint and OneDrive data: Check that all SharePoint and OneDrive data has been migrated correctly, including documents, images, and videos.
• Verify other data: Check that any other data that needed to be moved has been migrated correctly.
• Communicate: Finally, communicate with stakeholders that the migration is complete and provide any necessary training on the new system.

In summary

Important steps to remember for Microsoft 365 tenant-to-tenant migration:

1. Create a detailed migration plan that outlines the entire process.
2. Communicate the migration plan with all stakeholders involved.
3. Prepare the source and target tenants before starting the migration process.
4. Test the migration process in a non-production environment before performing the actual migration.
5. Follow the migration plan closely and monitor the migration process.
6. Address any issues that may arise promptly.
7. Perform post-migration tasks, including verifying that all data has been migrated correctly and updating any necessary configurations.

Microsoft 365 tenant-to-tenant migration can be a complex process. However, by following best practices such as planning, preparation, testing, and post-migration tasks, you can ensure a successful migration. Remember to communicate the migration plan with all stakeholders involved, monitor the migration process closely, and address any issues promptly.