The statute doesn’t distinguish between business or personal account nor does it mention using the SSN vs EIN to determine coverge. It does say the account holder must be a natural person and the name of the account holder must appear in the financial institution’s records as the direct or beneficial owner. If you have a sole proprietor account that meets these criteria the account would be covered under the rule even if the sole proprietor has an EIN. Again, the account holder would need to meet the criteria above and you would need to do an account review to determine if there are protected funds/protected amount.