Can a Google Tag Manager container be moved to a different account?

After wishing I could do the same and researching it, I have found the answer to be: No.

You can import and export, but you cannot modify the common GTM ID (ie. GTM-XXXXXX), and since you must import into an existing container, whatever you import is associated with that container ID.

It would be very nice to be able to move these around, but I'm sure the reason for not allowing it is that Accounts might be owned and managed by different companies or users, and moving containers between such environments could become very complicated just in terms of permission.

Yes, you can.

On the new account make a container, note it's id (GTM-XXXXX)

Export the container from the old account. Then open the JSON in a text editor, find and replace all instances of the old id with the new one from the new account.

Next, find and replace all instances of accountId and containerId to the new account's id and the new container's id (these can be found in the URL when you are logged in to the new account and viewing the container)

Then save the JSON and import