The default_customer_payment_term is not intended to be a fallback value. The payment term is not required on the invoice so customer may have no payment term.

Currently, if there is no payment term associated to the party, a user error is generated when generating the related invoice of a health service document. It does not check for the system-wide default payment term.

Similarly to the Account Receivable search process, the payment term should follow this logic:

            """ Look for the payment term in the following order:
                * Party
                * Default payment term in accounting config
                * Raise an error if there is no payment term
            """