Step by step  Guide to Preserving Custom Objects If you are merging leads with the same emails 

After merging leads in Marketo, you will lose custom objects (CO) if the merging process is not handled carefully. The connection between the CO and the final object-lead is always broken if CO does not belong to the winning-primary lead. At the same time, the object itself – CO remains in the Marketo without the reference to any lead. That’s why we call them – orphaned custom objects.

To avoid orphaned custom objects during the lead merge process in Marketo follow these steps.

  1. Before merging, you first need to get a list of records that have custom objects. For that create a smart list in Marketo with a filter that identifies all relevant leads who have your custom object. For example – filter “Has Car” if your custom object is called “Car”.
  2. Then using this list you need to get the actual data of each instance of a custom object. We advise to use the API and extract the data based on the smart list created in step 1.

    All fields are not needed completely, only link field and dedupe field. Marketo Custom Objects (CO) records are linked with person records (Leads) by a set link field value. By using the Marketo API and an external script (for example NodeJS), a CSV file should be generated as output.

    The final .csv table will look like:
Email addressCO 
[email protected]CO 1
[email protected]CO 2
[email protected]CO 3


In this example the link field is “Email address” and dedupe field is “CO” .

  1. After that, you can merge leads – manually or by bulk merging. 
  1. After the merge is complete, import the extracted file to re-establish any orphaned custom objects and link them to the primary leads. Please note that this activates all triggers that must be activated after getting a new CO.

With careful planning and completing all the above mentioned steps, it is possible to avoid losing any custom objects during the lead merge process in Marketo.

#Marketo #merge #lead_merge #deduplication #custom_objects #MarketoAPI #NodeJS