# Issue with Conversations API when sending message to a thread (actorId required/invalid) **URL:** \ **Category:** APIs & Integrations\ **Tags:** developer-tools, professional\ **Created:** [July 11, 2025, 4:31pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090 "2025-07-11T16:31:25Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![SistOnlinua](https://avatars.discourse-cdn.com/v4/letter/s/4af34b/32.png) [@SistOnlinua](https://community.hubspot.com/u/SistOnlinua)\ **Post date:** [July 11, 2025, 4:31pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/1 "2025-07-11T16:31:25Z")
Hi everyone, I’m currently integrating HubSpot’s Conversations API into a custom ticketing system on our website, and I’m running into an issue with the endpoint for **sending a message to an existing thread.** **Context:** 1. A user submits a form on our website, which creates a ticket via a HubSpot form connected as a ticketing channel. 2. Our customer support team replies to the ticket from within HubSpot’s platform. 3. We want the user to be able to reply from our website, and have their message appear in the same conversation thread. To achieve this, I’m using the endpoint _/conversations/v3/threads/{threadId}/messages._ The problem is related to the actorId field inside the recipient object. According to the documentation and some community posts, I understand that there was an **update in 2023** stating that actorId is no longer required when sending a message. However: - If I use the **previous format** (actorId: “E-[email]”), I get an error saying the format is invalid. - If I **omit the actorId** entirely (as the 2023 update suggests), the response says that the actorId field is required. So I’m stuck between two contradictory behaviors, and I haven’t found a valid way to identify the recipient when sending a new message to an existing thread. Has anyone faced this issue or found a working solution? Or is there any alternative way to allow a user to reply from a website frontend while keeping the message inside the same thread in HubSpot? Any help or guidance would be greatly appreciated. Thanks! ---
**Author:** ![Jaycee\_Lewis](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jaycee_lewis/32/61352_2.png) [@Jaycee\_Lewis](https://community.hubspot.com/u/Jaycee_Lewis)\ **Post date:** [July 11, 2025, 11:47pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/2 "2025-07-11T23:47:28Z")
Hey, @SistOnlinua 👋 If you link me to the exact documentation and some of the community posts, I will set up a quick test to see if we can work it out. — Jaycee ---
**Author:** ![SistOnlinua](https://avatars.discourse-cdn.com/v4/letter/s/4af34b/32.png) [@SistOnlinua](https://community.hubspot.com/u/SistOnlinua)\ **Post date:** [July 14, 2025, 7:20pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/3 "2025-07-14T19:20:21Z")
Hi Jaycee, thank you so much for your reply! Here’s the documentation I’ve been following: 👉 [[Link to the Conversations API – _send a message to a thread_ endpoint]](https://developers.hubspot.com/docs/guides/api/conversations/inbox-and-messages#send-messages-to-threads) 👉 [[Link to the changelog or 2023 update post]](https://developers.hubspot.com/changelog/changes-to-actors-and-delivery-identifiers-in-the-conversations-api) Here’s a screenshot from Postman showing the request I’m sending and the error I’m getting: ![ERROR.jpg](https://d2qpr2jzcazej7.cloudfront.net/original/3X/b/1/b177056cdfbd3e2d4b14217c217058a740810244.jpeg) I really appreciate you taking the time to test it out 😄 Thanks again! Juan ---
**Author:** ![Jaycee\_Lewis](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jaycee_lewis/32/61352_2.png) [@Jaycee\_Lewis](https://community.hubspot.com/u/Jaycee_Lewis)\ **Post date:** [July 17, 2025, 11:43pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/4 "2025-07-17T23:43:24Z")
Thanks, @SistOnlinua 🙌 Let me take a lookand I’ll see what I get in my test. — Jaycee ---
**Author:** ![SistOnlinua](https://avatars.discourse-cdn.com/v4/letter/s/4af34b/32.png) [@SistOnlinua](https://community.hubspot.com/u/SistOnlinua)\ **Post date:** [July 18, 2025, 7:48pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/5 "2025-07-18T19:48:25Z")
Thank you! 🙌 ---
**Author:** ![SistOnlinua](https://avatars.discourse-cdn.com/v4/letter/s/4af34b/32.png) [@SistOnlinua](https://community.hubspot.com/u/SistOnlinua)\ **Post date:** [August 13, 2025, 3:45am UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/6 "2025-08-13T03:45:15Z")
Hi [@Jaycee\_Lewis](https://community.hubspot.com/t5/user/viewprofilepage/user-id/127074), Have you been able to find any workaround for the endpoint? I’ve been trying for a while but still haven’t had any success. 😪 ---
**Author:** ![Jaycee\_Lewis](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jaycee_lewis/32/61352_2.png) [@Jaycee\_Lewis](https://community.hubspot.com/u/Jaycee_Lewis)\ **Post date:** [September 17, 2025, 9:21pm UTC](https://community.hubspot.com/t/issue-with-conversations-api-when-sending-message-to-a-thread-actorid-required-invalid/136090/7 "2025-09-17T21:21:19Z")
Hey, @SistOnlinua 👋 HubSpot has since expanded the [Conversations API](https://developers.hubspot.com/docs/api-reference/legacy/conversations/guide), but `actorId` represents a HubSpot actor rather than an email address; the old `E-[email]` actor type was removed, so email recipients should be identified using delivery identifiers rather than an `E-` actor ID. If you are still following the docs and getting an unexpected error, I’d suggest making a submission to the **[Developer Feedback](https://developers.hubspot.com/feedback)** form. It’s not a support form, but it’s the best place to submit feedback and issues that are reproducible with the documentation. — Jaycee _Moderator Note: this post was reviewed for relevancy and optimized for clarity on September 30, 2026. Thank you for your contributions to the HubSpot Community!_