[ADD] General: Multi Company

closes odoo/documentation#9960

Signed-off-by: Jessica Rogers (jero) <jero@odoo.com>
Co-authored-by: ksc-odoo <73958186+ksc-odoo@users.noreply.github.com>
Co-authored-by: Sam Lieber (sali) <36018073+samueljlieber@users.noreply.github.com>

content/applications/general.rst

@@ -7,6 +7,7 @@ General settings
     general/apps_modules
     general/users
     general/companies
+    general/multi_company
     general/iot
     general/email_communication
     general/integrations

content/applications/general/companies.rst

@@ -133,6 +133,8 @@ appears.
 
    For more information on pricing, see `Odoo's pricing <https://www.odoo.com/pricing-plan>`_ page.
 
+.. _general/employee-access:
+
 Employee access
 ===============
 
@@ -189,6 +191,8 @@ Document Layout` and edit the information as needed.
 populated from the company information listed, when navigating here: :menuselection:`Settings app
 --> Companies section --> Manage Companies`, and select a company from the list.
 
+.. _general/inter-company:
+
 Inter-company transactions
 ==========================
 

content/applications/general/multi_company.rst

@@ -0,0 +1,115 @@
+=============
+Multi-company
+=============
+
+.. |mcd| replace:: multi-company database
+
+In Odoo, multiple companies can exist within a single database. This allows for some data to be
+shared among companies, while still maintaining some level of separation between entities.
+
+Before deciding to use the multi-company feature, there are several factors to consider.
+
+.. important::
+   Multi-company is **only** available in *One App Free* databases, or with `Custom
+   <https://www.odoo.com/pricing-plan>`_ plans.
+
+Accessing multiple companies
+============================
+
+The list of :ref:`companies an employee has access to <general/employee-access>` in a |mcd| can be
+found at the top-right of the main Odoo menu bar, where the active company is listed. Click on the
+company name to reveal a list of all allowed companies. To switch to a different company, click on
+the company name in the drop-down menu. To enable multiple companies at once, tick the checkbox next
+to each desired company name.
+
+.. figure:: multi_company/company-access.png
+   :align: center
+   :alt: An example of the list of companies a user has access to when logged into a database.
+
+   An example of a user with access to multiple companies. The current company is My Company (San
+   Francisco), while My Company (Chicago) is also active.
+
+.. note::
+   The database may refresh after each checkbox is ticked.
+
+.. _general/active-companies:
+
+Multiple active companies
+-------------------------
+
+If more than one company is active at a time, one company is highlighted in purple, and is listed on
+the menu bar. This is the considered the *current* company.
+
+When creating a new record, the current company is added to the record in the *Company* field,
+except under the following circumstances:
+
+- The *Company* field for a new product, or a new contact, is left blank.
+- If there is a related document already in the system, the *Company* field on the new record
+  defaults to the same company.
+
+.. example::
+   Mitchell Admin has multiple companies enabled, but the current company is `My Company (Chicago)`.
+   When he creates a new product record, the :guilabel:`Company` field is left blank by default.
+
+   When he creates a new sales team, the :guilabel:`Company` field automatically defaults to `My
+   Company (Chicago)`.
+
+Sharing data
+============
+
+In a |mcd|, certain records are able to be utilized by all of the companies (or several, based on
+permissions).
+
+Products
+--------
+
+In an |mcd|, new products are created with the :ref:`Company field <general/active-companies>`
+blank, by default. If the *Company* field remains blank, the product is shared across all companies.
+
+Contacts
+--------
+
+Similar to products, contact records are shared across companies, by default. To limit access to a
+single company, click the :ref:`Company field <general/active-companies>` on a contact form, and
+select a company to assign the contact to.
+
+Inter-company transactions
+==========================
+
+The :ref:`Inter-Company Transactions <general/inter-company>` feature allows for one company in the
+database to sell or purchase goods and services from another company within the same database.
+Counterpart documents for orders and invoices can be automatically generated and synchronized,
+depending on the configuration settings.
+
+.. warning::
+   To ensure inter-company transactions are handled appropriately, certain configurations, such as
+   fiscal positions and localizations, need to be accurately assigned. See :ref:`Inter-Company
+   Transactions <general/inter-company>` for additional information.
+
+Use cases
+=========
+
+Multinational companies
+-----------------------
+
+A multinational retail chain, which operates in the United States and Canada, needs to manage
+transactions in both USD and CAD currencies.
+
+Additionally, because both countries have different tax laws and regulations, it is in the best
+interest of the customer to utilize the multi-company feature.
+
+This allows for inter-company transactions they need to manage inventory moves across international
+borders, while making it simple to sell to customers in both countries in their own currency.
+
+Separate processes
+------------------
+
+A small furniture company is developing a new line of products that require a separate procurement,
+inventory, and manufacturing process. The new products are drastically different from the existing
+catalog. The company is considering utilizing the multi-company feature to treat this new line as a
+different entity.
+
+To keep their database from becoming overly complex, the furniture company does not need to add an
+entirely new company. Instead, they can take advantage of existing features, such as :doc:`analytic
+accounting <../finance/accounting/reporting/analytic_accounting>`, and multiple warehouses, to
+manage the new product line, without having to overly complicate transactions.