Using 2 de-dupe fields on a custom object

[John_Teixeira]

We have set up a custom object with a one to many relationship with the lead. (Lead can have multiple Invoices). Instead of using a random number generated by the API (InvoiceID) can I use a combination of 2 de-dupe fields (LeadID and DebtorID) to dedupe? Where if the system sees that if the value of these 2 columns ever match that that is a duplicate? In the example below Invoice 1 and 4 would be duplicates. Is this possible? If it is, do I just indicate that both LeadID and DebtorID are both de-dupe fields? Or is something else required?

InvoiceID 1: (LeadID = 1) & (DebtorID = 1) DUPLICATE

InvoiceID 2: (LeadID = 1) & (DebtorID = 2)

InvoiceID 3: (LeadID = 2) & (DebtorID = 1)

InvoiceID 4: (LeadID = 1) & (DebtorID = 1) DUPLICATE

[Simon_Merrick1]

Did you ever get an answer on this from Marketo themselves? I can see you have no response from the community... I have a similar problem with multiple records with identical email addresses belonging to more than one workspace. I would like to add a custom dedupe field but not sure where to start...

[SanfordWhiteman]

Are you talking about Custom Objects in your case? Or Leads/People? 

[Kim_Gandy1]

Sanford Whiteman, I'm curious what your response is for custom objects with the above scenario. 

[Angus_McCann1]

Just wanted to follow up on this. Using two de-dupe fields means that in BOTH of those fields - in this case Lead ID and Debtor ID - need to be matched in order for the original custom object to be overwritten, correct?