diff --git a/docs/guides/index.rst b/docs/guides/index.rst
index f7f4b5ad30c..fc7bbaffcfa 100644
--- a/docs/guides/index.rst
+++ b/docs/guides/index.rst
@@ -46,3 +46,14 @@ These guides will help you customize or tune aspects of Read the Docs.
     sitemaps
     specifying-dependencies
     wipe-environment
+
+
+Read the Docs for Business how-to guides
+----------------------------------------
+
+These guides are specific to :doc:`/commercial/index`.
+
+.. toctree::
+   :maxdepth: 1
+
+   private-submodules
diff --git a/docs/guides/private-submodules.rst b/docs/guides/private-submodules.rst
new file mode 100644
index 00000000000..36b97afc676
--- /dev/null
+++ b/docs/guides/private-submodules.rst
@@ -0,0 +1,113 @@
+Using Private Git Submodules
+============================
+
+.. warning::
+
+   This guide is for :doc:`/commercial/index`.
+
+Read the Docs uses SSH keys (with read only permissions) in order to clone private repositories.
+A SSH key is automatically generated and added to your main repository, but not to your submodules.
+In order to give Read the Docs access to clone your submodules you'll need to add the public SSH key to each repository of your submodules.
+
+.. note::
+
+   You can manage which submodules Read the Docs should clone using a configuration file.
+   See :ref:`config-file/v2:submodules`.
+
+
+.. contents:: Table of contents
+   :local:
+   :backlinks: none
+   :depth: 2
+
+
+Copy your project's SSH Key
+---------------------------
+
+You can find the public SSH key of your Read the Docs project by
+
+#. Going to the :guilabel:`Admin` tab of your project
+#. Click on :guilabel:`SSH Keys`
+#. Click on the fingerprint of the SSH key (it looks like ``6d:ca:6d:ca:6d:ca:6d:ca``)
+#. Copy the text from the ``Public key`` section
+
+.. note::
+
+   The private part of the SSH key is kept secret.
+
+Add the SSH key to your submodules
+----------------------------------
+
+GitHub
+~~~~~~
+
+For GitHub, Read the Docs uses `deploy keys with read only access <https://developer.github.com/v3/guides/managing-deploy-keys/#deploy-keys>`__.
+Since GitHub doesn't allow you to reuse a deploy key across different repositories,
+you'll need to use `machine users <https://developer.github.com/v3/guides/managing-deploy-keys/#machine-users>`__
+to give read access to several repositories using only one SSH key.
+
+#. Remove the SSH deploy key that was added to the main repository on GitHub
+
+   #. Go to your project on GitHub
+   #. Click on :guilabel:`Settings`
+   #. Click on :guilabel:`Deploy Keys`
+   #. Delete the key added by ``Read the Docs Commercial (readthedocs.com)``
+
+#. Create a GitHub user and give it read only permissions to all the necessary repositories.
+   You can do this by adding the account as:
+
+   - A `collaborator <https://help.github.com/en/github/setting-up-and-managing-your-github-user-account/inviting-collaborators-to-a-personal-repository>`__
+   - An `outside collaborator <https://help.github.com/en/github/setting-up-and-managing-organizations-and-teams/adding-outside-collaborators-to-repositories-in-your-organization>`__
+   - A `team in an organization <https://help.github.com/en/github/setting-up-and-managing-organizations-and-teams/adding-organization-members-to-a-team>`__
+
+#. Attach the public SSH key from your project on Read the Docs to the GitHub user you just created
+
+   #. Go to the user's settings
+   #. Click on :guilabel:`SSH and GPG keys`
+   #. Click on :guilabel:`New SSH key`
+   #. Put a descriptive title and paste the
+   #. :ref:`public SSH key from your Read the Docs project <guides/private-submodules:Copy your project's SSH key>`
+   #. Click on :guilabel:`Add SSH key`
+
+GitLab
+~~~~~~
+
+For GitLab, Read the Docs uses `deploy keys with read only access <https://docs.gitlab.com/ee/ssh/#deploy-keys>`__,
+which allows you to reuse a SSH key across different repositories.
+Since Read the Docs already added the public SSH key on your main repository,
+you only need to add it to each repository of your submodules.
+
+#. Go to the project of your submodule on GitLab
+#. Click on :guilabel:`Settings`
+#. Click on :guilabel:`Repository`
+#. Expand the :guilabel:`Deploy Keys` section
+#. Put a descriptive title and paste the
+#. :ref:`public SSH key from your Read the Docs project <guides/private-submodules:Copy your project's SSH key>`
+#. Click on :guilabel:`Add key`
+#. Repeat the previous steps for each submodule
+
+Bitbucket
+~~~~~~~~~
+
+For Bitbucket, Read the Docs uses `access keys with read only access <https://confluence.atlassian.com/bitbucket/access-keys-294486051.html>`__,
+which allows you to reuse a SSH key across different repositories.
+Since Read the Docs already set the public SSH key on your main repository,
+you only need to add it to each repository of your submodules.
+
+#. Go to the project of your submodule on Bitbucket
+#. Click on :guilabel:`Settings`
+#. Click on :guilabel:`Access keys`
+#. Click on :guilabel:`Add key`
+#. Put a descriptive label and paste the
+#. :ref:`public SSH key from your Read the Docs project <guides/private-submodules:Copy your project's SSH key>`
+#. Click on :guilabel:`Add key`
+#. Repeat the previous steps for each submodule
+
+Others
+~~~~~~
+
+If you are not using any of the above providers.
+Read the Docs will still generate a pair of SSH keys.
+You'll need to add the :ref:`public SSH key from your Read the Docs project <guides/private-submodules:Copy your project's SSH key>`
+to the main repository and each of its submodules.
+Refer to your provider's documentation for the steps required to do this.