# Adding sub-issues

Learn about using sub-issues to break down your work into tasks.

You can add sub-issues to an issue to break down larger pieces of work into tasks. Your sub-issues show their relationship to the parent issue allowing you to track your work across GitHub. Parent issues and sub-issue progress is also available in your projects, allowing you to build views, filter, and group by parent issue.

Your sub-issues can themselves contain sub-issues, allowing you to create full hierarchies of issues that visualize entire projects or pieces of work and show the relationships between your issues.

You can add up to 100 sub-issues per parent issue and create up to eight levels of nested sub-issues.

## Creating a sub-issue

1. Navigate to the issue that you want to add a sub-issue to.
2. At the bottom of the issue description, click **Create sub-issue**.
3. In the dialog, type the title for your sub-issue.
4. Optionally, type the description for your issue, and set the issue type and any assignees, labels, projects, and milestones.
5. Optionally, if you want to continue create sub-issues for this parent issue, select **Create more sub-issues**.
6. Click **Create**.

## Adding an existing issue as a sub-issue

1. Navigate to the issue that you want to add a sub-issue to.

2. At the bottom of the issue description, next to "Create sub-issue", click <svg version="1.1" width="16" height="16" viewBox="0 0 16 16" class="octicon octicon-triangle-down" aria-label="View more sub-issue options" role="img"><path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg>.

   ![Screenshot of the sub-issues section below the issue description. The "View more sub-issue options" button is highlighted with an orange rectangle.](/assets/images/help/issues/sub-issue-drop-down.png)

3. In the drop-down menu, click **Add existing issue**.

4. Select the issue that you want to add as a sub-issue.
   * Select an issue from one of the suggestions.
   * In the "Search issues" field, type an issue title or issue number, then click on the results.
   * To add issues from other repositories, click <svg version="1.1" width="16" height="16" viewBox="0 0 16 16" class="octicon octicon-arrow-left" aria-label="Back to repository selection" role="img"><path d="M7.78 12.53a.75.75 0 0 1-1.06 0L2.47 8.28a.75.75 0 0 1 0-1.06l4.25-4.25a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L4.81 7h7.44a.75.75 0 0 1 0 1.5H4.81l2.97 2.97a.75.75 0 0 1 0 1.06Z"></path></svg> next to the repository name and select a different repository.