When creating new properties for CRM objects via the HubSpot APIs, both a type and fieldType value are required. The type value is used to determine what data can be stored in the property, while the fieldType value is used to determine how the field is presented in the HubSpot app. There’s a close correlation between the type and fieldType values, and setting a type and fieldType that don’t work together can result in unexpected behavior for the user.

Up until now, we have not been validating that type and fieldType values were being used correctly. Starting on February 1, 2021 we’ll be enforcing this validation for our newer “v3” endpoints, documented on the Properties API page and the Custom Objects API page. After that date, requests with incorrectly correlated type and fieldType values will return an error. We’ve added more information about the relationship between type and fieldType to our documentation to assist you in making any required updates to your code.

Note that older versions of these property-creating APIs (the CRM Object Properties API, the Contact Properties API, and the Company Properties API) will continue to work without this validation, so no changes are required on integrations using those APIs. New integrations should use the newer, "v3" APIs.

If you have any questions or comments, please leave a note in the forum thread.