Marketo de-duplication and customzation

Marketo de-duplication and customzation

The standard technique of Marketo de-duplication for new-records is by email address. If records already exist in the marketo with similar email address then record will be updated with new/missing information only and if email address is not found then new record will be created.

Do you know you can customize the de-dup rule in Marketo?
See, de-dup customization is only viable when you have some other unique field (like email address) tagged with your lead then only it will be useful for your business.

For example:
I am into education domain and one lead can be tagged with the college name only once then you can use college name as your secondary key for de-duplication rule

If you set up a custom de-dup rule, Marketo will match on email as primary key, and another field as a secondary key. For example, if you add college name as a secondary de-dup field then see the scenario below:

Case 1: When lead entered the database for the first time, email address was “” and college name was “XYZ”

Marketo Action - New lead is created

Case 2: Lead entered the database with same email address “” but college name is different. College name is “ABC” then de-dup rule will check primary key first that is email address {Primary key matched} then it will check secondary key, college name which is different {Secondary key mis-matched}
Marketo Action: New lead is created with same email address but different college name

Case 3: Lead entered the database with same email address and college name as case 1 but this time it’s also tagged with mobile number and home address. Marketo will match primary key and secondary key {Match perfect}
Marketo Action: Lead created with case 1 will be updated with new information

Custom de-dup rules apply to list uploads, form submissions and most API integration but It does not apply to the native CRM sync like salesforce / Microsoft dynamics. These CRM uses their own de-dup rule and that is based on CRM ID.

I hope this blog will help you to understand Marketo de-duplication rule.


Sant Rathore

Best regards,
Sant Singh Rathaur
Level 10 - Community Moderator

Re: Marketo de-duplication and customzation

The terms "primary key" and "secondary key" are used incorrectly here.

A custom de-deduplication rule means you're using a compound de-duplication key (a key composed of multiple underlying fields). But it's neither a primary key, secondary key, nor unique key (there's absolutely no requirement in the database for the compound key to be unique, thus you should not use those terms as they will cause -- and have caused -- confusion when talking about Marketo with in-house IT or really any technical folks).

The compound key is correctly described as: a means of locating a lead when a pre-check of the database is performed, which only occurs via some input methods. Those inputs do include form posts from previously anonymous Munchkin sessions; they don't include all API connections, nor previously associated Munchkin sessions, nor flow steps, nor CRM integrations.

Re: Marketo de-duplication and customzation

Hi Sanford Whiteman Thank you for correcting my mistake. I am learning a lot from your comments and blogs.

Best regards,
Sant Singh Rathaur