Only the board owner, who has access to several workspaces, can move boards between them
To move a board to a different account, click the three-dot menu > Move to account and specify the destination. The list will show you all the accounts you have access to.
Moving a board to a different account
If some members of the board are not a part of the destination team — their access to the board will be denied:
The warning message when moving a board from one Team account to another
In this case, you can copy the list of users and add them to your team before moving the board so the collaborators retain access (or you may also want to re-add them to the board after it's moved). If the number of users is less than 10, you can see the list by clicking View users emails. If the number is greater than 10, there will be a link to download the list.