You attempt to migrate a site collection and get the following error message:

The site collection URL could not match the name of the Microsoft 365 Group at the destination. You can delete the Microsoft 365 Group ‘{0}’ that was created by this operation and try again in 24 hours.

When the operation stops, you find an empty site collection with a number at the end of its URL in the destination that does not match your Microsoft 365 Group.

When a Microsoft 365 Group or site collection is deleted, it can take up to 24 hours for Microsoft 365 to erase all traces of the site collection associated to your Microsoft 365 Group or site collection.

If you try to migrate a Microsoft 365 Group with the same name within 24 hours of the deletion, the application will likely detect that the name of the associated site collection is locked at the destination.

This detection can only be made after the new Site Collection is created with an added number in its URL at the destination in the migration process (for example, mysitecollection becomes mysitecollection1).

Because the operation creates a Microsoft 365 Group and associated site collection with the wrong URL at the destination, you will have to delete the Microsoft 365 Group and restart your migration. We suggest waiting twenty-four hours to ensure any reference to your desired Microsoft 365 Group name is cleared in Microsoft 365.