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
- Navigate to the issue that you want to add a sub-issue to.
- At the bottom of the issue description, click Create sub-issue.
- In the dialog, type the title for your sub-issue.
- Optionally, type the description for your issue, and set the issue type and any assignees, labels, projects, and milestones.
- Optionally, if you want to continue create sub-issues for this parent issue, select Create more sub-issues.
- Click Create.
Adding an existing issue as a sub-issue
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Navigate to the issue that you want to add a sub-issue to.
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At the bottom of the issue description, next to "Create sub-issue", click .

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In the drop-down menu, click Add existing issue.
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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 next to the repository name and select a different repository.
Working with sub-issues using GitHub CLI
GitHub CLI is an open source tool for using GitHub from your computer's command line. When you're working from the command line, you can use the GitHub CLI to save time and avoid switching context. To learn more about GitHub CLI, see About GitHub CLI.
To create a new issue as a sub-issue of an existing parent, use the --parent flag with gh issue create. The parent can be specified by issue number or URL.
gh issue create --title "TITLE" --body "ISSUE-DESCRIPTION" --parent PARENT-ISSUE-NUMBER
To add existing issues as sub-issues of a parent, use the --add-sub-issue flag with gh issue edit. The flag accepts a comma-separated list of issue numbers or URLs.
gh issue edit PARENT-ISSUE-NUMBER --add-sub-issue SUB-ISSUE-NUMBER
To remove a sub-issue from its parent, use --remove-sub-issue on the parent or --remove-parent on the sub-issue.
gh issue edit PARENT-ISSUE-NUMBER --remove-sub-issue SUB-ISSUE-NUMBER
gh issue edit SUB-ISSUE-NUMBER --remove-parent