Submit data to a form via API



We have the HubSpot form, which receives data from site via API:

We’ve been following the documentation for integration. But the contacts we receive are changing names to “Newsletter Subscriber”:

It is very strange for us. The “First name” is still correct for a couple of minutes, but after some time it becomes “Newsletter”, and “Last name” becomes “Subscriber” all of a sudden:

Please, can anyone explain this?

Best regards,


Hi @plum

Do you have any other integration with HubSpot in addition to the forms? That last screenshot shows that the name was updated using the Contacts API.


Hi, dadams

Yes, I have integration with another form which shows by js code. But the form on the screens integrated only once and works via the Forms API (I searched by form_id in the site files). I don’t use the Contacts API on the site. The update of names happens only with contacts which I send via the Forms API. When I used the same form by js code the contacts did not update.

I don’t know why but if I use js code the contact name shows email address on the list:

It is my form:

Best regards,


@plum based on the screenshots, the form itself is working correctly, but that change source of API would mean that some separate integration using the Contacts API was modifying the contact record after the form submission.

Has anyone else on your team set up any external integrations that would be able to modify your contacts?


Hi dadams,

Thank you for help with this issue. You are right - the problem was related with third-party extension that changed the names.

Best regards,