It's not possible to transfer company data from one Fathom account to another. It is also not possible to merge two Fathom accounts.
To move data into another account, you will need to delete the company from one account, and set it up again in another account.
Any 'Administrator' users in your account can delete a company. You can delete a company in the My Companies screen, by hovering over the selected company and clicking the three dots at the end of the row. From here you can delete the selected company.
Recommended: if you have customised the company that you'd like to transfer, we recommend that you screenshot any custom KPIs (including formulas) and download any custom reports so that they are more easily replicated in the new account.