Getting Started - Adding HubSpot registration to existing .Net web application



I am a .Net developer. I work on a couple web sites that allow people to register as users / customers. This registration data is currently being synced with mailing lists at Mail Chimp. Our company is migrating from Mail Chimp to Hub Spot. I have been requested to replace the Mail Chimp sync with calls to Hub Spot to add users as they register. I am not sure yet if they will allow users to unsubscribe via our sites.

What is the fastest and easiest way to add contacts(?) to Hub Spot with data we are collecting on a C# web site?


Hi @e.shattuck,

If you’re using a custom form to register users, you could submit that data via the forms API. Otherwise, you’d likely want to use the tracking code API or the contacts API; docs for all of these are listed below.


After some review, we decided to use the Forms API. This is partially working for us, but we are having a problem getting the fields to match up with the fields on the Contact card. I am doing the coding on our web site. Our Marketing department are the ones inside HubSpot. So, I don’t know if they are giving me the proper field names, or if they have the HubSpot forms wired up right.


Hi @e.shattuck,

If you’re submitting via the forms API, the fields that appear in the HubSpot forms UI aren’t relevant. The forms API will accept a submission with any valid fields. The following Knowledge Base article has some info on how to find the internal property name that you may want to pass along to the marketing department: