Unexpected Workflow Enrollments Triggered by Webhook Events Without Object Match

[LFDias]

Hello Community Team,

We’ve been experiencing unexpected enrollments in one of our workflows. This workflow is triggered only by webhook events, not by property changes or manual actions.

Starting on November 3rd, we noticed a large spike in enrollments — several deals entered the workflow even though the incoming webhook events did not include the external_id (HubSpot Deal ID) that should be used for record matching.

After reviewing the Event Manager, we confirmed that the events were successfully received but had no associated object ID. Despite that, HubSpot still enrolled existing deals as if a random match had been made.

We’d like to understand:

1. Whether this behavior (enrolling records even when no object match is provided) is expected or a recent change in how webhook-triggered workflows are processed.

2. How HubSpot determines which record to associate when a webhook event arrives without an objectId or matching property.

3. If there are any recommended settings or safeguards we can apply to prevent this kind of unintended enrollment.

We’ve already added a validation filter in the workflow to only process events when the HubSpot ID is known, but we’d like to confirm the underlying cause and whether there’s any fix or documented behavior change related to this.

Thank you in advance for your help and clarification.

Best regards,
Luiz Felipe Dias.
Nexforce — Developer Team

[HubDoPete · Accepted solution]

Hi @LFDias and thanks @BérangèreL for the tag,

Here is the relevant help doc that specifically addresses Enrolling an object in a workflow based on a third-party incoming webhook

Your screenshot show what looks to be a list of Deals that were enrolled in a workflow, and you have a column called "HubSpot ID" but I am not sure what that column is. It cannot be the object ID of the deal, as that cannot be blank on deals that exist.

You must nominate which data property in the third-party Webhook is to be used to identify the unique existing deal.  Then the workflow can only be triggered if the selected third-party webhook property has a non-empty value in the incoming webhook data.

I suggest:

• If you are sure that the property you nominated as the object ID is sometimes blank, if possible, stop the third-party from sending webhooks that have no unique ID for the workflow to use.

• Check the workflow logs for deals that you think should not have enrolled, to see why the object enrolled
• If you are sure that the mapped third-party property was blank, yet the workflow triggered and enrolled an object, that's a topic for HubSpot support to take a closer look.

best

Pete

[LFDias]

Hi team,

Thanks for the clarification. I’d like to add some important details about what we are observing on our side regarding the object identifier used in the incoming webhook.

In our integration, the property shown as “HubSpot ID” in the screenshot is exactly the field we mapped as the unique match between the third-party system (ZapSign) and HubSpot Deals. This is the property that should identify which existing deal the webhook refers to.

Here’s what we’ve confirmed through testing and logs:

1. When the webhook arrives with this property empty, the workflow is still triggered, and HubSpot ends up associating the event to an unrelated deal.
   This results in what appears to be a random or incorrect match.

2. When the webhook arrives with this property filled but no deal matches that ID, the expected behavior occurs: no object is enrolled, and nothing is triggered.

This means the unexpected enrollments only occur in the scenario where the mapped object-ID property is empty, which seems inconsistent with the expected behavior described in the documentation.

As a temporary safeguard, I added a validation directly on the workflow trigger so that it only fires if the event’s “HubSpot ID” property is known and not empty. This prevents the incorrect enrollments, but it does not address the underlying issue:
the workflow should not be triggering at all when the identifier property is empty.

Given the operational impact and the risk of incorrect deal updates, I believe this behavior may require deeper investigation from HubSpot’s side.

Please let me know if you need specific examples, timestamps, or event IDs — I can provide several cases where the property was empty but the workflow still fired.

Thank you for your support.

Best regards,
Luiz Felipe Dias.

[BérangèreL]

Hi @LFDias and thanks for the additional information!

As @HubDoPete suggested, I would also recommend connecting with HubSpot Technical Support, as Support is included in your subscription and they will be able to provide real-time assistance for this matter, including hopping on a screenshare if necessary.

I hope that you'll get sorted soon!

Thanks and I look forward to seeing you around the Community!

Have a lovely day! 🌞
Bérangère

[BérangèreL]

Hi @LFDias and thanks for reaching out to the HubSpot Community!

Here are some resources on the topic that might help:

- Use webhooks with HubSpot workflows
- Webhooks API

I'd love to put you in touch with our Top Experts: Hi @HubDoPete, @Mike_Eastwood and @Bortami do you have suggestions to help @LFDias, please?

Have a wonderful day and thanks so much!
Bérangère