Sync values between parent & subitem

Sync values between parent & subitem

TL;DR: Keep parent item and subitem values in sync — copy a value from parent to subitem on creation, mirror parent changes onto existing subitems, copy back the other way, or apply conditional sync rules. Pick the recipe that matches your trigger and direction.

When to use these automations

  • You want subitems to inherit a value from the parent — automatically
  • You want subitems to stay in sync when the parent changes
  • You want the reverse direction — push subitem changes back to the parent
  • You need conditional sync (only some subitems, only when empty, only on creation, etc.)

Before you start

  • The same column type must exist on both parent and subitem (e.g. both Status, both Date)
  • Column names do not need to match — you map them in the automation setup
  • Read-only columns (Mirror, Formula, Last updated) cannot be the destination

Pick the recipe that fits your workflow

1. Sync parent values to subitems on creation

Recipe: "When subitem is created, set value of its column to match value of column in parent."
What it does: Copies a parent column value to the subitem the moment the subitem is created. Existing subitems are not touched.
Use when: You want every new subitem to inherit a value, but don't want existing subitems to update later when the parent changes.
Example: Parent item has an Owner. Every new subitem should automatically get the same owner. If the parent's owner changes later, existing subitems stay as they were.

2. Sync parent values to subitems on every change

Recipe: "When column changes on an item, change its subitems column to the same value."
What it does: Updates all existing subitems whenever the parent column changes.
Use when: Subitems must always mirror the parent — even after creation.
Example: Parent Status changes from Working on it to Done. All subitems' Status updates to Done automatically.

3. Sync subitem changes back to the parent (subitem → parent)

Recipe: "When subitem column changes, copy that value to this column on parent item."
What it does: Reverse direction — when a subitem column changes, the value flows up to the parent.
Use when: A specific subitem (e.g. a "Status" or "Latest update") should drive the parent's column.

4. Sync only for subitems matching a status condition

Recipe: "When parent item column changes, and only if subitem status/label is something, copy that value to this subitem column."
What it does: Updates a subitem only if its Status matches the condition you set.
Use when: Some subitems should follow the parent, others should stay frozen.
Example: Parent Due Date changes. Only subitems with Status = Not Started receive the new date. Subitems marked Done are left alone.

5. Sync only when the subitem column is empty

Recipe: "When subitem is created, set the value of its column to match the value of column in its parent item, only when the subitem column is empty."
What it does: Copies a parent value only if the subitem column has no value yet — never overwrites manual input.
Use when: Users sometimes fill subitem values manually and you want to respect those.

6. Use a parent column as the subitem name

Recipe: "When a subitem is created, change its name to the value of this column in its parent item."
What it does: Sets a new subitem's name based on a parent column value.
Use when: Subitems should always be named after a specific parent attribute.
Example: Parent has a Client Name column. Every new subitem is automatically named after the client.

7. Sync a Mirror column value

Recipe: "When subitem is created, copy the value from its parent item mirror column to this column."
What it does: Copies a value from a parent's Mirror column into a subitem column. (Mirror columns can't normally be the source of a sync — this recipe handles that case.)
Use when: Parent items pull data from connected boards via Mirror columns and subitems need that same data.

8. Sync connected item names into a Text column (on creation)

Recipe: "When subitem is created, copy the name/s of the connected items in the parent item's connected column to the subitem's text column."
What it does: Copies the names of items connected to the parent into a Text column on the subitem.
Use when: Subitems need a static, exportable reference to connected items without maintaining a live link.

9. Re-sync connected item names when the parent's connected column changes

Recipe: "When item's connected column changes, copy the name of the connected items in the parent item's connected column to subitem's text column."
What it does: Same as #8, but the trigger is a parent connected-column change rather than subitem creation. Subitems stay in sync as connections evolve.

Common gotchas

  • Read-only columns can't be the destination. Mirror, Formula, and Last-updated columns can't receive synced values.
  • Column types must match. Status → Status. Date → Date. You can't sync a Status to a Date.
  • Recipe choice changes behavior. "On creation" recipes never re-fire. "On parent change" recipes update existing subitems. Pick based on when you want it to run.
  • Conditions are case-sensitive. "Not Started" ≠ "not started" when used as a condition.

How to choose the right recipe

Three quick questions:
    When should the sync fire? On creation, on every parent change, or only sometimes?
    Should all subitems be updated? Or only some — by name, by status, or only if empty?
    Should manual values be preserved? If yes, use the "only when empty" variant.

Deep-dives

Related

  •  Date & timeline automations⁠  (date-specific syncs)
  •  Create subitems automatically⁠  (set defaults on creation)
  •  Smart rules & by-name automations⁠  (per-name and conditional sync rules)
  •  Full recipe library⁠ 

Still stuck?

Email  hello@fantasymedia.io  and we'll help you pick the right recipe for your workflow.