This is a critical need for my organization. The majority of our events have a limited number of spots and we are desperately trying to find a workaround. This seems like it should be a basic function of capturing event registrations and I would imagine most marketing teams using HubSpot would agree with this sentiment.
Hi all,
I managed to implement something similar to this using the HubSpot Analytics API and modifying the embed code. It’s not perfect but does the job. You can check out what I did via the link below. I recorded a video walking through the solution and also listed a few points on what to keep in mind. Like I said it’s not perfect but it might help someone achieve their goals in the meantime.
The embed code looks something like this (you can also see it if you view the source of the page above):
hbspt.forms.create({
portalId: "PORTAL_ID",
formId: "FORM_ID",
onFormReady: function($form, e) {
document.querySelector("[type='submit']").addEventListener("click", function(event) {
event.preventDefault();
var requestURL = "http://jack.emea-tc.com/forms/submit-control/get-submissions.php";
$.ajax({
url: requestURL,
success: function(result) {
var json = JSON.parse(result);
console.log(json.totals.submissions);
if (json.totals.submissions > 10) {
$(".formContainer .alert span").html(json.totals.submissions);
$(".formContainer .alert").show();
} else {
$form.submit();
}
}
});
}, false);
}
});
Well, it’s been 2 years, and 115 upvotes, so hopefully this will be taken into consideration soon. 
Any news on this? We really need this feature as we have many events with limited number of spots available.
One of our clients is now looking for other software (Splash) since HubSpot does not do this automatically. How can we speed this up?
+1 to this idea. Please implement this! Either let us set a limit on form submissions or list size - something to help us with limiting registrations for events / webinars / etc!
Hi HubSpot Community,
My name is Joe, I’m the Ideas Forum Manager. I wanted to thank you for your thoughtful comments on this post. Your feedback helps us build better products.
I think this a great Idea! I’m happy to say we are currently reviewing this request and its feasibility. At this time I don’t have any details around timing or delivery, but all updates will be relayed on this thread.
I am changing the status of this idea to Being Reviewed as our team scopes out this work.
Best,
Joe
I would like this feature. It good for an RSVP page with limited number of seats
This is critical. Prioritize the development of this functionality, please.
Please, yes.
Please, please add this feature. Especially in the world of COVID when event sizes are very governmentally regulated, this is so crucial.
Can’t wait for this feature! 
I was looking for a way to do this as well. We need to cap submissions (or better, let others join the waiting list). So instead of the form not allowing more submissions, maybe have an automation that sends the first X number of submissions one email, and the rest another one (“you’re on the waiting list”).
Checking in to see if there is a solution for this yet and if so, can it be used for limiting the number of times a field on a dropdown property is selected before being removed as an option?
As far as I know, no.
@hubspot - Get on the ball and get back in touch with us all! Many of us are paying customers who could greatly benefit from this feature. The process by which communications for feature requests, in my experiences, is woefully lacking.
We’d like to see this implemented. It’s a low effort, high impact feature request.
Yes and I would love to take that a step further to disable a form after a property has reached a certain number. If a person submits a form and requests 2 people, that property would calculate sum and close the form when it reaches a capacity. Similar to how ticket selling works.
I would love to see functionality like this introduced. We’re currently planning for an event and due to social distancing/covid restrictions, we have to set capacities on presentation slots contacts can register for, so having an automated process which removes certain properties when they’ve reached a limit would be really helpful rather than keeping an eye on numbers and manually removing options in the sign up form.
Hi!
Commenting on this idea here
This form will be great since it can act like a “booking” form as well capped to a certain number.
Would appreciate this even more if we can have a 1 per IP or 1 per email option for this (:
It would be especially helpful if this was something that could be both turned on an off as well as used to trigger other actions in the portal. For example in Workflows something like:
Trigger [Action X] when [Form Y] receives [Z number of submissions]. Being able to use the number of submissions across the tool would make this feature immeasureably useful!