The global message entered in the Statement setup will be printed on all Debtor statements. 

Enter global messages to display on all debtor statements:

1.On the Setup ribbon, select Documents setup.

2.Select the Statement setup tab.

 documents-setup-statement-setup-tab

3.Enter the message in up to 3 lines to display on the Debtor statements

4.Click on the OK button. 

Enter statement messages for specific debtor accounts: 

1.On the Action ribbon, select Debtors (F4).

2.Select the debtor (customer / client) account.

3.On the Delivery address tab, enter a message of up to 3 lines. 

4.Click on the Save button.