What is an offboarding checklist?

It is the list you work through the day someone stops working with you - staff, contractor, agency or bookkeeper:

• Disable the account, do not just change the password - and end active sessions, which a password change alone may not.
• Remove them from shared systems - social accounts, the website admin, the accounting file, the payment terminal.
• Change shared credentials they knew, since those cannot be taken off one person.
• Collect the equipment and record it against your asset register.

Do it the same day. In a month it will be neither fresh nor awkward, just forgotten.