Use-case: Currently, we are migrating subscriberkey to a uniqueID for all subscribers SFMC is being used as independent platform (NO SFDC is connected or involved).

Concern: Considering, we have some campaigns for prospects, after the key migration we will still have subscribers being added to AllSubscribers & All Contacts with emailaddress as SubscriberKey.

When these prospects will become customers, they will be added to AllSubscribers & All Contacts with uniqueID as SubscriberKey. Hence, there will be duplicates in AllSubscribers (since there will be same person's entry twice, one with emailaddress as SubscriberKey and other with uniqueID as SubscriberKey).

1. When John was added to SFMC as a prospect

2. When John is added to SFMC as a customer

Possible Solution:

  1. Run a SQL query to identify subscribers from AllSubscribers / All Contacts with SubscriberKey LIKE '%@%'
  2. Run a SQL query to check if these same subscribers existing in AllSubscribers / All Contacts with SubscriberyKey NOT LIKE '%@%'
  3. Extract duplicate subscribers with emailaddress as SubscriberKey in a DataExtension

Question: Now, when I am running this possible solution everyday via automation studio, how to delete the extracted duplicate subscribers from AllSubscribers & All Contacts in an automated fashion on daily basis (NOT looking for a manual approach).

  • You can use WSProxy to delete them from All Subscribers list, but they would still remail in All Contacts and you would be billed for them - so a better solution would be to use Contact Delete (using a data extension) to delete them from Marketing Cloud completely.
    – zuzannamj
    Jul 27, 2022 at 17:42
  • Hi @zuzannamj the link you shared is not working. Are you suggesting SSJS solution to programmatically delete the contacts from All Subscribers and All Contacts by triggered the contact delete API endpoint? Is there any other way within SFMC UI to delete contacts from All Subscribers and All contacts in an automation fashion (if building a custom API process is not possible in our use-case)?
    – kl2
    Jul 27, 2022 at 18:34
  • Nope, there isn’t - but why aren’t you able to use the API? There are ready solutions that you can literally copy and paste into the script activity in automation studio, eg. salesforce.stackexchange.com/questions/245799/…
    – zuzannamj
    Jul 27, 2022 at 19:32
  • Thank you @zuzannamj for sharing, I will take a look.
    – kl2
    Jul 27, 2022 at 21:44