How to set interest charges for unpaid invoices

Set up interest charges for unpaid sales invoices in company settings in Sage 50 Accounting.

Go to Setup, Settings, Receivables/Customers & Sales, then and Options.
Select Interest Charges.
Select One-Time Simple Interest or Compound Interest. See how One-Time Simple Interest and Compound Interest work.
Enter a percentage and number of days.

Interest calculates on outstanding invoices based on the number of days you've selected and will calculate only once.