[ADD] accounting: using payment terms

Written by Fabien Pinckaers (Odoo)
Proofread by Johan Bosma (Onestein)

accounting/receivables/customer_invoices/payment_terms.rst

@@ -1,3 +1,101 @@
 ================================
 Defining and using payment terms
 ================================
+
+Payment terms define the conditions to pay an invoice. They apply on
+both customer invoices and supplier bills.
+
+Example, for a specific invoice:
+
+-  Pay 50% within 10 days
+
+-  Pay the remaining balance within 30 days
+
+.. note::   Payment terms are different from invoicing in several times. If,
+            for a specific order, you invoice the customer in two parts, that's not
+            a payment term but invoice conditions.
+
+Configuration
+=============
+
+Configure your usual payment terms from the Configuration menu of the
+Account application. The description of the payment term is the one that
+appear on the invoice or the sale order.
+
+A payment term may have one line (ex: 21 days) or several lines (10%
+within 3 days and the balance within 21 days). If you create a payment
+term with several lines, be sure the latest one is the balance. (avoid
+doing 50% in 10 days and 50% in 21 days because, with the rounding, it
+may not do exactly 100%)
+
+.. todo:: screenshot payment term forms, after QDP have commited the change
+          planned on this object
+
+Using Payment Terms
+===================
+
+Payment terms for customers
+---------------------------
+
+Payment terms can be set on:
+
+- **a customer**: to apply this payment term automatically on new
+  sale orders or invoices for this customer. Set payment terms on
+  customers if you grant this payment term for all future orders of
+  this customer.
+
+- **a quotation**: to apply this payment term on all invoices
+  created from this quotation or sale order, but not on other
+  quotations
+
+- **an invoice**: to apply the payment term on this invoice only
+
+If an invoice has a payment term, the journal entry related to the
+invoice is different. Without payment term or tax, an invoice of $100
+will produce this journal entry:
+
++----------------------+------------+---------+----------+
+| Account              | Due date   | Debit   | Credit   |
++======================+============+=========+==========+
+| Account Receivable   |            | 100     |          |
++----------------------+------------+---------+----------+
+| Income               |            |         | 100      |
++----------------------+------------+---------+----------+
+
+If you do an invoice the 1st of January with a payment term of 10%
+within 3 days and the balance within 30 days, you get the following
+journal entry:
+
++----------------------+------------+---------+----------+
+| Account              | Due date   | Debit   | Credit   |
++======================+============+=========+==========+
+| Account Receivable   | Jan 03     | 10      |          |
++----------------------+------------+---------+----------+
+| Account Receivable   | Jan 30     | 90      |          |
++----------------------+------------+---------+----------+
+| Income               |            |         | 100      |
++----------------------+------------+---------+----------+
+
+In the customer statement, you will see two lines with different due
+dates.
+
+Payment terms for vendor bills
+------------------------------
+
+The easiest way to manage payment terms for vendor bills is to record a
+due date on the bill. You don't need to assign a payment term, just the
+due date is enough.
+
+But if you need to manage vendor terms with several installments, you
+can still use payment terms, exactly like in customer invoices. If you
+set a payment term on the vendor bill, you don't need to set a due date.
+The exact due date for all installments will be automatically created.
+
+.. seealso:: 
+
+    :doc:`cash_discounts`
+
+.. rst-class:: text-muted
+
+| Written by Fabien Pinckaers (Odoo)
+| Proofread by Johan Bosma (Onestein)