Subtasks break a task into smaller pieces of work. Each subtask is a full task: it has its own assignee, start and due dates, status, priority, description, tags, estimate, attachments and custom fields, and its own comments, where you can @mention colleagues. Your team can track time and book schedule time against it. A subtask can have subtasks of its own, so you can split a deliverable into phases, and each phase into single actions.

To add or change subtasks, you need the Update task permission on the project (the project's settings, Members tab, under Task Permissions), or the Administrator role.

Add a subtask

  1. Open the parent task and click the Subtasks tab, the tree icon next to Summary. The figure beside the icon shows how many subtasks are complete, such as 1/2 for one of two.

    Subtasks tab of a task, showing 1/2 by the tab icon and listing two subtasks, one complete, with the Add button and the + Add a new subtask link

  2. Click Add, or + Add a new subtask under the list.

  3. Type the title. Optionally pick a task type (the icon on the left), an assignee, and a Due Date. Tick Notify to send the assignee a notification.

  4. Click Save, or press Enter to save and start the next subtask straight away.

A new subtask takes its parent's section, its task type (unless you pick another) and its Everyone or Team Only visibility. To fill in the rest, click the arrow at the end of the subtask's row on the Subtasks tab. The subtask opens in the same task window as any task, with all the same tabs, and a link at the top takes you back to the parent.

You can also turn an existing task into a subtask, as shown below.

See subtasks in your views

  • List: a task with subtasks has an arrow on the left. Click it to show the subtasks, indented under the parent, with the same columns and inline editing. To open or close every level at once, use Expand in the toolbar, then Expand all subtasks or Collapse all subtasks.
  • Board: click the arrow on a card to show its subtasks as indented cards below it, each with the parent's name at the top.
  • Gantt and Calendar: subtasks with dates appear like other tasks. On the calendar, the parent's name follows the subtask's title.
  • My Tasks and All Tasks: subtasks sit alongside other tasks, with the parent's name next to the title.

The List and Board show five levels: the top task and four levels below it. A deeper subtask opens from its parent's Subtasks tab. It still appears in the Gantt, the calendar and My Tasks.

The badge next to a task's title, such as 2/5, counts its direct subtasks: here two of five are complete. It updates as soon as anyone changes a subtask's status. On the List and Board, hover over a parent task's time icon to see the estimated, actual and remaining hours for the task itself, for all its subtasks, and in total. The task's Task Timesheets tab shows the same totals: see subtask time and estimate roll-up.

To see only top-level tasks, open Filter and tick Hide Subtasks.

Reorganise the task tree

In the List, drag a task by the six-dot handle on the left:

  • Make it a subtask: drag it over the task that should become its parent and move the pointer slightly to the right, until an indented line appears. On the Board, hold the card over the parent card until the parent is highlighted.
  • Make it a top-level task again: drag the subtask out of its parent, next to a top-level task. Dragging a subtask into another section also makes it a top-level task in that section.
  • Change the order: drag subtasks up or down within their parent. In the List this needs the Sort set to Manual Sort. You can also drag subtasks into order on the parent's Subtasks tab.

After a drag that changes a parent, a message such as "Moved under Design landing page" appears with an Undo link for 10 seconds. You can't rearrange the tree by dragging while Hide Subtasks is on, or in My Tasks.

You can also use the ⋮ menu, at the end of a task's row in the project or at the top right of the task window:

  • Assign New Parent: choose the new parent from the tasks in the same project, then click Update. This works for top-level tasks too.
  • Remove from Parent: turns the subtask into a top-level task, at the bottom of the same section. Use it when a subtask grows into a piece of work of its own.

When a task moves, its subtasks go with it, keeping their structure. A subtask always stays in its parent's section, so its Section field can't be changed. To move a task and its subtasks to another project, see moving tasks between projects.

Track time, schedules and billing

  • Timesheets: subtasks are listed under their parent in the task list of a time entry, and you can start a timer on a subtask's row. On the timesheet's Day and Week views, time logged on a subtask shows a subtask icon. Log time on the subtask rather than the parent, so your reports show exactly where the time went. See getting started with timesheets.
  • Resource scheduling: bookings can be linked to a subtask. The booking's tooltip shows the parent task and the subtask. See resource scheduling and project tasks.
  • Invoices: billable time on subtasks is added to invoices like any other time. In the invoice's Add Time window, the Filter Sections/Tasks list shows a subtask as "Subtask < Parent task". See invoicing time, expenses and fixed amounts.
  • Reports: time and schedule reports include entries on subtasks. The Task List report leaves subtasks out at first: untick Exclude Subtasks to include them, and add the Parent Task column. The task export includes subtasks, with a Parent Task column.

Recurring subtasks

A subtask can repeat like any task, on paid plans. Set it up on the subtask's Recurring Settings tab (the circular arrow icon). The tasks it creates are independent top-level tasks, not subtasks, and any subtasks of the recurring subtask aren't copied. The tab shows a note about this. See recurring tasks.

Delete a subtask or its parent

Delete a subtask like any task, from the ⋮ menu. Deleting a parent task deletes all its subtasks, at every level.

A task can't be deleted while it, or any of its subtasks, has time entries, schedule bookings or expenses linked to it, or fixed amounts that have been invoiced. Remove those links first. Deleting needs the Delete task permission on the project, or the Administrator role.