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 an Existing Lists criteria type, added in the Conditions stage like any other criterion.

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.
• Identify contacts who are not in any selected list.
• Combine existing lists with additional list rules.
• Reduce duplication of complex list logic.

Existing list filter options

When you add this criteria type, choose one of the following comparison options:

• Include — return contacts who are in the selected list.
• Exclude — leave out contacts who are in the selected list.
• Is empty — return contacts who are not in any of 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. Go to the Conditions stage and add a new condition.
4. Select Existing Lists as the criteria type.
5. Choose the comparison option:
   • Include
   • Exclude
   • Is empty
6. Select the list or lists you want to reference.
7. Add any additional criteria, combining them with AND/OR logic as needed.
8. Open Results to preview the matching contacts, then Save the list.

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 you reference a live list, changes to that list automatically flow through to any list that depends on it — referenced lists are evaluated dynamically as they 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.

What does "is empty" mean?

It returns contacts who are not in any of the selected lists.

Does this update automatically?

Yes. Referenced lists are evaluated dynamically, so changes to a referenced list are reflected as it changes.

Why is this useful?

It simplifies list management and reduces duplication of complex logic.