How to Delete or Deactivate Lookup Filters in Salesforce?

From the managements settings for the relationship field’s object, go to Fields.
Scroll to the Custom Fields & Relationships related list.
Click the name of the field containing the lookup filter.
Click Edit.
To deactivate the lookup filter, deselect Enable this filter, then save your changes.
Deactivating a lookup filter preserves the lookup filter configuration but:
- Prevents it from applying to the relationship field
- Prevents it from impacting the cross-object references limit
- Removes it as a dependency for fields referenced in the lookup filter criteria
To delete the lookup filter, click Clear Filter Criteria, then save your changes.
Deleting a lookup filter permanently removes it. You can’t recover deleted lookup filters.