Hubspot - Create Associations fields with Custom Objects

Hi, I am setting up integration using (formerly Integromat) with Hubspot to try and acheive the following: 1) Create a new record in our Custom Object, and then 2) Associate that new record in the Custom Object with an existing Contact record.

I have no problem creating a new Custom Object record, but am having trouble trying to identfy the correct Object ID and Object Type for both the Contact record and Custom Object record, as well as figuring out what the “Custom Object ID” is. See screenshot below.


  1. There is a “To” and a “From” - I am trying to create an association between a Contact and a Custom Object, I am assuming “To” should be the Custom Object and the “From” should be a Contact record? I see a reference article here but want to confirm the correct association is Contact>Custom Object. Right?

  2. How do I find the “Custom Object ID” and do I choose Hubspot Defined or User Defined for the “Category”

  3. Finally, where do I find the “Definition ID” for the relationship between a Contact>Custom Object. There is a table that is for existing object associations but I imagine new ID is defined specifically for your Contact>Custom Object that was created.

Any help would be great!

Hi- The Hubspot API documentation unfortunately does not provide more info about how to associate the custom object with Contact’s record or any different type of record.
“From” should be the Custom Object. Into the Form Object Type, you should enter an ID of that Custom Object, into the From Object ID - there should be the Custom Object record ID.
The “To Object Type” field should have the value “contacts”
To Object ID - enter the Contact record ID.
But what is not clear from the Hubspot API Doc is the Custom Definition ID.
As you can see here: CRM Associations API Overview the Custom Object to another object is not specified.
Hubspot support should help with this field.