[ADD] Sales: How to manage prices for B2B (tax excluded) and B2C (tax included)?

https://docs.google.com/document/d/1kExheNd2VgEe-_go6uaQXEBXIj5eWvTe0x63EBk_W9I/edit#

sales.rst

@@ -10,3 +10,4 @@ Sales
    sales/overview
    sales/quotation
    sales/invoicing
+   sales/products_prices

sales/products_prices.rst

@@ -5,3 +5,4 @@ Products & Prices
 .. toctree::
    :titlesonly:
 
+   products_prices/prices

sales/products_prices/prices.rst

@@ -5,3 +5,4 @@ Prices Management
 .. toctree::
    :titlesonly:
 
+   prices/B2B_B2C

sales/products_prices/prices/B2B_B2C.rst

@@ -0,0 +1,169 @@
+===================================================================
+How to manage prices for B2B (tax excluded) and B2C (tax included)?
+===================================================================
+
+When working with consumers, prices are usually expressed with taxes
+included in the price (e.g., in most eCommerce). But, when you work in a
+B2B environment, companies usually negotiate prices with taxes excluded.
+
+Odoo manages both use cases easily, as long as you register your prices
+on the product with taxes excluded or included, but not both together.
+If you manage all your prices with tax included (or excluded) only, you
+can still easily do sales order with a price having taxes excluded (or
+included): that's easy.
+
+This documentation is only for the specific use case where you need to
+have two references for the price (tax included or excluded), for the
+same product. The reason of the complexity is that there is not a
+symmetrical relationship with prices included and prices excluded, as
+shown in this use case, in belgium with a tax of 21%:
+
+-  Your eCommerce has a product at **10€ (taxes included)**
+
+-  This would do **8.26€ (taxes excluded)** and a **tax of 1.74€**
+
+But for the same use case, if you register the price without taxes on
+the product form (8.26€), you get a price with tax included at 9.99€,
+because:
+
+-  **8.26€ \* 1.21 = 9.99€**
+
+So, depending on how you register your prices on the product form, you
+will have different results for the price including taxes and the price
+excluding taxes:
+
+-  Taxes Excluded: **8.26€ & 10.00€**
+
+-  Taxes Included: **8.26€ & 9.99€**
+
+.. note::
+  If you buy 100 pieces at 10€ taxes included, it gets even more
+  tricky. You will get: **1000€ (taxes included) = 826.45€ (price) +
+  173.55€ (taxes)** Which is very different from a price per piece at
+  8.26€ tax excluded.
+
+This documentation explains how to handle the very specific use case
+where you need to handle the two prices (tax excluded and included) on
+the product form within the same company.
+
+.. note::
+  In terms of finance, you have no more revenues selling your
+  product at 10€ instead of 9.99€ (for a 21% tax), because your revenue
+  will be exactly the same at 9.99€, only the tax is 0.01€ higher. So, if
+  you run an eCommerce in Belgium, make your customer a favor and set your
+  price at 9.99€ instead of 10€. Please note that this does not apply to
+  20€ or 30€, or other tax rates, or a quantity >1. You will also make you
+  a favor since you can manage everything tax excluded, which is less
+  error prone and easier for your salespeople.
+
+Configuration
+=============
+
+Introduction
+------------
+
+The best way to avoid this complexity is to choose only one way of
+managing your prices and stick to it: price without taxes or price with
+taxes included. Define which one is the default stored on the product
+form (on the default tax related to the product), and let Odoo compute
+the other one automatically, based on the pricelist and fiscal position.
+Negotiate your contracts with customers accordingly. This perfectly
+works out-of-the-box and you have no specific configuration to do.
+
+If you can not do that and if you really negotiate some prices with tax
+excluded and, for other customers, others prices with tax included, you
+must:
+
+1.  always store the default price TAX EXCLUDED on the product form, and
+    apply a tax (price included on the product form)
+
+2.  create a pricelist with prices in TAX INCLUDED, for specific
+    customers
+
+3.  create a fiscal position that switches the tax excluded to a tax
+    included
+
+4.  assign both the pricelist and the fiscal position to customers who
+    want to benefit to this pricelist and fiscal position
+
+For the purpose of this documentation, we will use the above use case:
+
+-   your product default sale price is 8.26€ price excluded
+
+-   but we want to sell it at 10€, price included, in our shops or
+    eCommerce website
+
+Setting your products
+---------------------
+
+Your company must be configured with price excluded by default. This is
+usually the default configuration, but you can check your **Default Sale
+Tax** from the menu :menuselection:`Configuration --> Settings` 
+of the Accounting application.
+
+.. image:: media/price_B2C_B2B01.png
+  :align: center
+
+Once done, you can create a **B2C** pricelist. You can activate the
+pricelist feature per customer from the menu: 
+:menuselection:`Configuration --> Settings` of the Sale application. 
+Choose the option **different prices per customer segment**.
+
+Once done, create a B2C pricelist from the menu 
+:menuselection:`Configuration --> Pricelists`. 
+It's also good to rename the default pricelist into B2B to avoid confusion.
+
+Then, create a product at 8.26€, with a tax of 21% (defined as tax not
+included in price) and set a price on this product for B2C customers at
+10€, from the :menuselection:`Sales --> Products`
+menu of the Sales application:
+
+.. image:: media/price_B2C_B2B02.png
+  :align: center
+
+Setting the B2C fiscal position
+-------------------------------
+
+From the accounting application, create a B2C fiscal position from this
+menu: :menuselection:`Configuration --> Fiscal Positions`. 
+This fiscal position should map the VAT 21% (tax excluded of price) 
+with a VAT 21% (tax included in price)
+
+.. image:: media/price_B2C_B2B03.png
+  :align: center
+
+Test by creating a quotation
+============================
+
+Create a quotation from the Sale application, using the 
+:menuselection:`Sales --> Quotations` menu. You should have the 
+following result: 8.26€ + 1.73€ = 9.99€.
+
+.. image:: media/price_B2C_B2B04.png
+  :align: center
+
+Then, create a quotation but **change the pricelist to B2C and the
+fiscal position to B2C** on the quotation, before adding your product.
+You should have the expected result, which is a total price of 10€ for
+the customer: 8.26€ + 1.74€ = 10.00€.
+
+.. image:: media/price_B2C_B2B05.png
+  :align: center
+
+This is the expected behavior for a customer of your shop.
+
+Avoid changing every sale order
+===============================
+
+If you negotiate a contract with a customer, whether you negotiate price
+included or price excluded, you can set the pricelist and the fiscal
+position on the customer form so that it will be applied automatically
+at every sale of this customer.
+
+The pricelist is in the **Sales & Purchases** tab of the customer form,
+and the fiscal position is in the accounting tab.
+
+Note that this is error prone: if you set a fiscal position with tax
+included in prices but use a pricelist that is not included, you might
+have wrong prices calculated for you. That's why we usually recommend
+companies to only work with one price reference.