GnuCash has an integrated accounts receivable system. The
transactions generated by the A/R system are recorded within the Accounts
Receivable account. You generally do not work directly with this account.
You generally work with the four integrated GnuCash A/R application
components available through the → sub-menu. These four components are:
Customers are people or companies to whom you sell products or services on credit.
Invoices represent the physical invoice you send to a customer to request payment. This invoice contains an itemized list of things you sold.
In addition, GnuCash also has support for Credit Notes which represent the inverse of Invoices. A credit note is usually handed to a customer to correct items that were incorrectly invoiced or returned.
Both document types will be set up using the same menu items. Credit notes were introduced starting with
GnuCash stable release 2.6.0.
Jobs (optional) is where you register Customer Jobs. Jobs are a mechanism by which you can group multiple invoices to a particular customer.
Process Payments is used to register payments you received from a customer.