[ADD] accounting: new shared accounts feature documentation

In 18.0 was the shared accounts feature added to Odoo but the documentation
doesn't contain any data related to it. This commit brings information about
said feature in the documentation.

task-4485674

Author: Megaaaaaa

content/applications/finance/accounting.rst

@@ -82,9 +82,12 @@ Multi-company
 =============
 
 Several companies can be managed within the same database. Each company has its :doc:`chart of
-accounts <accounting/get_started/chart_of_accounts>`, which is also useful to generate consolidation
-reports. Users can access several companies but can only work on a single company's accounting at a
-time.
+accounts <accounting/get_started/chart_of_accounts>`, but it is possible to share accounts in
+between them for scenarios in which such a configuration would be required.
+
+.. seealso::
+   :ref:`Shared Accounts Feature <coa_shared_accounts>` and :doc:`Consolidation
+   <accounting/get_started/consolidation>`
 
 Multi-currency environment
 ==========================

content/applications/finance/accounting/get_started.rst

@@ -179,6 +179,7 @@ Get started with Stripe and enable secure integrated credit and debit card payme
 .. seealso::
    * :doc:`bank`
    * :doc:`get_started/chart_of_accounts`
+   * :doc:`get_started/shared_accounts`
    * :doc:`bank/bank_synchronization`
    * :doc:`../fiscal_localizations`
    * `Odoo Tutorials: Accounting and Invoicing - Getting started [video]
@@ -189,6 +190,8 @@ Get started with Stripe and enable secure integrated credit and debit card payme
 
    get_started/cheat_sheet
    get_started/chart_of_accounts
+   get_started/shared_accounts
+   get_started/consolidation
    get_started/multi_currency
    get_started/avg_price_valuation
    get_started/tax_units

content/applications/finance/accounting/get_started/chart_of_accounts.rst

@@ -169,6 +169,23 @@ To do so, check the :guilabel:`Allow Reconciliation` box in the account's settin
 .. image:: chart_of_accounts/chart-of-accounts-reconciliation.png
    :alt: Allow reconciliation for accounts in Odoo Accounting
 
+.. _coa_shared_accounts:
+
+Shared Accounts
+---------------
+
+This feature allows you to create a single account for a specific purpose and share it between
+multiple companies. It is especially useful for multi-company environments in which a similar
+account might be used across different companies.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_accounting.png
+   :alt: Shared accounts feature in Odoo Accounting
+
+.. note::
+   Check the :doc:`Shared Accounts <shared_accounts>` page for more information on the
+   :ref:`benefits of that feature <shared_accounts_benefits>` and :ref:`how to configure it
+   <setting_up_shared_accounts>`.
+
 Deprecated
 ----------
 

content/applications/finance/accounting/get_started/consolidation.rst

@@ -0,0 +1,116 @@
+=============
+Consolidation
+=============
+
+Using the :doc:`Shared Accounts <shared_accounts>` feature, you can consolidate the financial data
+of your multi-company but also multi-currency environments.
+
+Regardless of whether you have a multi-currency-environment or not, the consolidation is
+automatically done in the :ref:`reports <reporting>` of the accounting application. This allows you
+to have a single report and only have to select which companies you want to check the data of with
+the company selector in the top right corner of the screen.
+
+For :ref:`multi-currency setups <multi_currency>`, the system uses the :abbr:`CTA (Cumulative
+Translation Adjustment)` system to translate all amounts into the selected company's currency by
+default.
+
+.. _reporting:
+
+Reporting
+---------
+
+Consolidation in the reports
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In the reports, consolidation is done by summing up the values of the accounts that are shared
+between the companies. This allows you to have a **global view** of the financial situation of your
+whole group.
+
+Examples
+~~~~~~~~
+
+The setup of the following screenshots is a parent company having one invoice for an amount of
+10.000€ and a child company having one invoice for an amount of 1.000€. The account used for the
+invoices is a shared account between the two companies.
+
+This first screenshot shows the accounting report of the parent company which has a balance of
+10.000€.
+
+.. image:: consolidation/consolidation_reporting_first_company.png
+   :alt: Accounting report of the parent company in a shared account setup.
+
+This second screenshot shows the accounting report of the child company which has a balance of
+1.000€.
+
+.. image:: consolidation/consolidation_reporting_second_company.png
+   :alt: Accounting report of the child company in a shared account setup.
+
+This third screenshot shows when you select both companies in the company selector and head into
+the report. The balance is now 11.000€ which is the sum of the two invoices in the account.
+
+.. image:: consolidation/consolidation_reporting_both_companies.png
+   :alt: Accounting report of both companies in a shared account setup.
+
+.. _multi_currency:
+
+Multi-currency conversions
+--------------------------
+
+:abbr:`CTA (Cumulative Translation Adjustment)`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In the case of multi-currency environments, CTA is used to use a single currency for all the
+amounts in the report, the one from the **selected company**. CTA has three different methods
+of calculation which are chosen following the **type of account** used in the transaction
+which's currency has to be changed.
+
+#. For **Equity** accounts **except the retained earnings**, the CTA is calculated with the historical
+    rate which is the rate at the time of the transaction.
+#. For **Income**, **Expense** and **retained earnings** accounts, the CTA is calculated with the
+    average rate per day for the reported period.
+#. For other accounts like **Assets** and **Liabilities** accounts, the CTA is calculated
+    with the closing rate which is the last rate applied at the period's closing date.
+
+The use of this system may result in non balanced reports. This is due to the fact that the CTA
+can use a different rate for the payable and the receivable of a transaction which can lead to a
+difference in the total amount of the report. This is normal and to be taken into account.
+
+.. note::
+    It is possible to disable CTA in the options of a report under the label :guilabel:`Currency
+    Translation`. If you don't want to use CTA, you can select the option :guilabel:`Use the most
+    recent rate at the date of the report` instead of :guilabel:`Use CTA`.
+
+Examples
+~~~~~~~~
+
+The setup for the following screenshot is a parent company configured to use EUR as its currency.
+A second company configured to use USD as its currency and it has a single invoice for 10.000$ set
+in a shared account. That invoice was confirmed on the 1st of January 2025 when the **USD/EUR**
+rate was 1.0. The report is generated on the 31st of December 2025 when the rate is now 3.0.
+In between those two dates, a rate of 2.0 was applied on the 1st of July 2025. The company selected
+is the one using euros meaning all amounts in the report are translated to euros.
+
+This first screenshot shows how the CTA would calculate the amount of the invoice in dollars when
+translated to euros if the shared account was an **Equity** account. The CTA would use the rate at
+the time of the transaction which was 1.0. This means that the equity would be 10.000€ for an
+invoice of 10.000$ sent on the 1st of January 2025.
+
+.. image:: consolidation/consolidation_multi_currency_equity.png
+   :alt: CTA calculation for an Equity account in a multi-currency environment.
+
+This second screenshot shows how the CTA would calculate the amount of the invoice in dollars when
+translated to euros if the shared account was an **Income** account. The CTA would average the rate
+per day for the period which means that 181 days were at a rate of 1.0 USD/EUR, 183 days were at a
+rate of 2.0 and 1 day was at a rate of 3.0. Therefore the average per day would be of about 1.5068
+resulting in an equity of about 15.068€ for an invoice of 10.000$ sent on the 1st of January 2025.
+
+.. image:: consolidation/consolidation_multi_currency_income.png
+   :alt: CTA calculation for an Income account in a multi-currency environment.
+
+This third screenshot shows how the CTA would calculate the amount of the invoice in dollars when
+translated to euros if the shared account was an **Asset** account. The CTA would use the rate at
+the time of the closing date which was 3.0. This means that the amount would be of 30.000€ for an
+invoice of 10.000$ sent on the 1st of January 2025 resulting in a null balance for the report.
+
+.. image:: consolidation/consolidation_multi_currency_asset.png
+   :alt: CTA calculation for an Asset account in a multi-currency environment.

content/applications/finance/accounting/get_started/consolidation/consolidation_multi_currency_asset.png

@@ -0,0 +1,164 @@
+===============
+Shared Accounts
+===============
+
+In Odoo, it is possible to share accounts between multiple companies. This feature is particularly
+useful for businesses that operate under a **multi-company structure** and might benefit from a
+**unified chart of accounts**.
+
+In order to setup said feature, two ways are available: Either the :ref:`basic setup
+<setting_up_shared_accounts>` or using the :ref:`merge tool <merge_tool>`.
+
+In the same way the feature is accompanied by a merging tool that helps already established
+multi-company environments use the the new shared accounts feature, an :ref:`unmerge tool
+<unmerge_tool>` is also available for if you ever want to stop using the feature.
+
+The feature can also be used to do :doc:`consolidation` of the financial data of
+your multi-company environment. This allows you to have a **global view** of the financial situation
+of your whole group when you have child companies under a parent one.
+
+.. _shared_accounts_benefits:
+
+Benefits of Shared Accounts
+===========================
+
+1. Lighter load of accounts to handle
+-------------------------------------
+
+The main benefit of the shared accounts feature is to **reduce the amount of accounts** that have
+to be handled by the main accountant of a multi-company environment.
+
+.. example::
+   Environments that have two companies using the generic chart of accounts of the same country
+   used to have each accounts of that chart twice. With the shared accounts feature, it is possible
+   to have a single version of each of those accounts.
+
+2. Simplified and Cleaner Reporting
+-----------------------------------
+
+When auditing reports, the shared accounts feature grants a **lighter version of the reports**
+while **keeping all the data visible and accessible**. This makes it easier to understand and
+manage the accounts.
+
+.. example::
+   Auditing amounts in the balance sheet report of a company using a shared account with one of its
+   child companies and grouping by account used to show two groups for the two accounts that share
+   the same purpose. Now they are shown in the same group and are differentiable using the company
+   they are used in.
+
+3. Macro and Micro Management
+-----------------------------
+
+For the main companies as much as the last child company of a branch, using the shared accounts
+feature allows accountants to **handle the accounts at the level they need to**. This means that a
+main accountant can manage the accounts of all the child companies knowing exactly which one is
+meant for what even though it could have a totally different code in each company. For the child
+companies' accountants, it means they can manage the accounts of their company without ever having
+to consider the impact it could have on the other companies using the same account.
+
+.. example::
+   Even though the account is shared and is the same record in the database for all companies, its
+   code in any company can be modified without affecting the other companies granting more
+   flexibility in the management of the accounts.
+
+.. _setting_up_shared_accounts:
+
+Setting Up Shared Accounts
+==========================
+
+Enable Multi-Company
+--------------------
+
+To enable account sharing, you first need to enable the multi-company feature in Odoo. This can be
+done by simply making sure you have multiple companies setup in your Odoo database.
+
+Configure Shared Accounts
+-------------------------
+
+Once multi-company is enabled, you can configure shared accounts by going to an account you wish to
+share between companies. Head into the :guilabel:`Mapping` tab and enter the code you want for the
+account for each desired company.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_mapping.png
+   :alt: Configuring company relative codes for a shared account in Odoo Accounting
+
+From now on, your account will be taken into account for :doc:`consolidation` but is still not
+usable in the invoices of the companies you configured a code for. To add that possibility,you
+can head back to the :guilabel:`Accounting` tab and add your second company to the list of
+companies this account is available for.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_accounting.png
+   :alt: Adding a company to a shared account in Odoo Accounting
+
+.. _merge_tool:
+
+Merge Tool
+==========
+
+Use cases
+---------
+
+The merging tool is there to simplify the process of creating shared accounts. This tool is
+particularly useful when you have an **already setup multi-company environment** in which you were
+using separate accounts that you now want to merge.
+
+Steps
+-----
+
+To use the merge tool, you need to select all the companies that have an account you want to merge
+in the company selector in the top right corner of the screen.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_select_companies.png
+   :alt: Selecting all companies that have accounts to be merged.
+
+You can then select all the account that are to be merged, click the :guilabel:`Actions` button,
+and select the :guilabel:`Merge accounts` option in the drop-down.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_merge_action.png
+   :alt: Selecting the accounts to merge and the tool in the options.
+
+You will then enter a confirmation wizard where you can confirm the operation. Once all is set,
+you can click the :guilabel:`Merge` button to complete the process.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_confirmation_wizard.png
+   :alt: Confirmation wizard for the Merge Tool of the shared accounts feature.
+
+In the end, the selected accounts will be merged into a single shared account that is available for
+all the selected companies in the same way it would have been if the account had only been created
+on a single company and then configured to be shared like in the :ref:`basic setup
+<setting_up_shared_accounts>`.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_result.png
+   :alt: Result of the Merge Tool of the shared accounts feature.
+
+.. _unmerge_tool:
+
+Unmerge Tool
+============
+
+Use cases
+---------
+
+At the opposite end of the spectrum, the unmerge tool is there to simplify the process of stopping
+to share specific accounts. This tool finds its use when you have shared accounts that you want to
+**dissociate from certain companies** without losing the data that they contain.
+
+Steps
+-----
+
+Using any of the companies that have a shared account, it is possible to select it and unmerge it
+using the :guilabel:`Unmerge account` option in the :guilabel:`Actions` menu.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_unmerge_action.png
+   :alt: Selecting an account to unmerge and the tool in the options.
+
+This will open a confirmation window listing all the accounts that will be created.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_confirmation_wizard.png
+   :alt: Confirmation wizard for the Unmerge Tool of the shared accounts feature.
+
+In the end, each of the companies that had a code configured on the shared account will have a new
+account linked to no other company.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_result.png
+   :alt: Result of the Unmerge Tool of the shared accounts feature.