Filtering lists using existing lists

Filtering by Existing Lists lets you build a new list in the List Builder by referencing lists you have already created. Instead of rebuilding complex criteria, you include or exclude Contacts based on their membership in another list — reusing logic you have already perfected.

This is available within the List Builder as the Existing Lists field, added in the Conditions stage like any other criterion. For every other field, see List Builder field menus and operators (Document ID: 222).

What you can do

• Reference existing lists as part of your list criteria.
• Include contacts who belong to another list.
• Exclude contacts who belong to another list.
• Reference both live lists and fixed lists.
• Combine existing lists with additional list rules.
• Reduce duplication of complex list logic.

Existing list filter options

When you add this field, choose one of the following operators:

• Include — return contacts who are in the selected list.
• Exclude — leave out contacts who are in the selected list.
• Is empty / is not empty — test whether the contact has any membership in the selected lists.

Use an existing list in a new list

1. Open Lists from the left-hand menu.
2. Click Create list to start a new list, or open an existing list to edit it.
3. Click Next to go to the Conditions stage, then click Add Criteria.
4. In the field menu, choose Existing Lists.
5. Choose the operator:
   • include
   • exclude
   • is empty
   • is not empty
6. Select the list or lists you want to reference. Both live and fixed lists are offered.
7. Add any additional criteria, combining them with And/Or logic as needed.
8. Click Next to preview the matching contacts in Results, then save the list from the Actions stage or with Save and close.

Example use cases

• Build a list that includes everyone from a specific mailing list.
• Create a list of contacts who meet new criteria but are not in an existing list.
• Layer age, location or engagement rules on top of a pre-defined list.
• Reuse complex lists without duplicating their logic.
• Maintain cleaner, more maintainable list structures.

How it fits with the rest of the List Builder

• Existing Lists criteria work with both live lists and fixed lists.
• When a live list references another live list, changes to the referenced list flow through automatically. A fixed list built this way captures the members at the time it is created and does not change.
• This criteria type integrates fully with all other list criteria, supporting cleaner segmentation, campaigns and reporting.

FAQs

What does filtering by existing lists do?

It lets you include or exclude contacts based on their membership in another list.

Do I need to recreate list rules to reuse them?

No. You can reference an existing list directly rather than rebuilding its criteria.

Can I combine this with other criteria?

Yes. Existing list filters can be combined with any other list rules using And/Or logic — see Building conditions — rules, criteria and AND/OR logic (Document ID: 219).

What do "is empty" and "is not empty" mean?

They test whether the contact has any membership in the selected lists. To leave out the members of a particular list, exclude is usually the clearer choice.

Does this update automatically?

Yes, if the list you are building is a live list — changes to a referenced list are then reflected automatically. A fixed list does not update.

Why is this useful?

It simplifies list management and reduces duplication of complex logic.