Setting default terms for accounts receivable and accounts payable will populate all new customer or supplier files with the selected default terms. The default terms can be over ridden in the customer or supplier file or at the time of transaction entry.

To set the defaults go to :

Main Menu> Setup> Change Company Information> Sales and Invoicing Tab 

Select the Type of Payment you would like to flag as your default by clicking on the file folder next to that record.

Select the checkbox for either AP or AR default, select Done and that's it!