At the bottom of each Patient Bill you may see a possible statement. This is called "Include Notes On Statement" and is under Billing Setup in the Patient billing section. You may turn this off and on as you wish and write any custom statement you wish, based on what your clinic would like printed on the bottom of the Patient statement(s).
Navigate to Billing >> Patient Billing >> Detailed patient bills.
Click on Billing setup.
Change Note-1, Note-2, Note-3, Note-4 as per your requirement. Or select "No" against "Include Notes On Statement" if you don't want to show the statements. After making changes click "Save".
Enter values in the form to generate the bill. At the bottom of the bill changed note is displayed.
Same steps can be followed in "Overdue insurance & patient bill", "Overdure patient bills", "Patient bills by account type."