Confirm who is asking
Check that the request comes from the current owner or an authorised admin on the account.
Get the new owner's details
Ask for their name, email and role so the change is made once.
Handle billing first
Explain whether the card and invoices move with the account or need updating.
Make the change and check access
Transfer the ownership, then confirm the new owner can sign in and the old one no longer can.
Confirm in writing to both
Send a short note to both people saying what changed and when.
Plan for the owner who left
If the old owner is unreachable, ask for proof such as a company email or billing record.