Hello everyone,
We've been asked more and more frequently to use forms with fields in "read-only" mode for the recipient. In this scenario, the recipient would have only the option to register (or not) to an event for example.
As I've observed with the present forms, this is not possible. In the case of a subscription type form, the existent data is replaced by the new data. The landing page form will require to update the contact and prospect, or at least one of them (in order to not update anything at all, new elements are to be created, like a custom entity). The event-registration form, which works only on the portal, also allows to create new contacts and modify existing data on an existing contact.
We would highly appreciate to have a form that:
- does not create new contacts
- does not replace data on an existing contact
- allows to register to an event only to people that exist in the CRM
- allows to collect information on people who want or not to register for an event, in order to use this information as a trigger in future customer journeys / branches.

Thank you very much !
Needs Votes
Ideas Administrator

It is already possible to create a form that will not update the contacts or leads. You can create a Workflow to extract the values from a form submission. You can use this data to create a custom entity or to create or update any existing entity. Please refer to: Map form data to entities with custom Workflows (Dynamics 365 Marketing) | Microsoft Docs