We also need this ability! Our organization has an enterprise data warehouse that is the main source for customer data that is synced into Hubspot for marketing use, but it’s a one way sync (for legal reasons). Anyone that submits a form with the same email, the source data is overwritten (many of the organizations we work with have multiple contacts that use the same organization email address to sign up for newsletters or resources, so it happens a lot). We can get around the other form fields by making custom properties, but we don’t have a way to lock the Email from being overwritten.
Upvoting on behalf of my client - this would help keep their data up to date
+1 for this. This feature used to exist and was removed.
We had a client site erroneously update a contact email in HubSpot that had already been set and triggered a loop of email changing/rechanging that sent 10k “email changed” notifications.
Additionally, the fact that CRM Inbox doesn’t support reply-to addresses, means that HubSpot forms are the best way to get contact form inquiries into the inbox. If we now have to completely disable the non-HubSpot form setting to prevent erroneous updates, we have no reasonable way of getting these inquiries into the inbox.
Two Distinct Solutions for Preventing Overwrites
Thinking through this issue, there are actually two different scenarios at play:
Property-Level Protection: A setting to prevent fields from being overwritten once initialized, ensuring data integrity.
Workflow Assignment Control: A function that assigns values only if the field is blank, allowing workflows to populate missing data without unintentionally overwriting existing values.
Both are essential for different use cases, and having both options would make data handling far more robust and efficient! 
If I could vote for this option 1,000,000 times, I would. Smaller applications like JotForm and Survey Monkey have this basic functionality. If you’re using forms to collect data over a period of time, a form submission data export isn’t helpful -just one more document to maintain.
Can we please get this fixed.
yes please, weird this functionality is not already present. we should be able to change wether or not we like our clients to be able to unintentional change hubspotdata while submitting a webform. Typos and like are a huge operational risk for any company so please provide this function ASAP.
We need this, team!
Adding +1 here! Not having this sort of feature messes with the integrity of our CRM.
The DACH market operates as one market but certian messaging (event invites etc.) are only sent out to D, A or CH depending on where the content is relevant. We have a custom property but if someone comes across the D page for a download instead of an A page (Smart content here doesn’t work reliably to switch out an entire form) then the person will be shifted to the incorrect market internally.
Upvoting on behalf of the customer. They have a bidirectional integration with primary data system and there is a potential to overwrite some fields if submitting the form twice. Would be great to have an ability to lock crucial fields, such as name and surname, the first time the form is submitted.
Upvoting
Please add this! Users are overwriting their own data with typos, etc.
Upvoting this
This, or at least a second type of form, not overwriting existing data.
Hi Everyone,
Thank you all for taking the time to submit, vote and comment on this Idea.
I’m Sabari, the PM for HubSpot’s Forms tool.
This feature is on our backlog but there are no shareable timelines at the moment.
I will update the feature to “in development” once it’s actively being worked on. Keep an eye on this post in the meantime!
Regards,
Sabari