# Issue with Scheduling Callback via Zoom API **URL:** \ **Category:** API and Webhooks\ **Tags:** api\ **Created:** [April 15, 2026, 1:31pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993 "2026-04-15T13:31:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 15, 2026, 1:31pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/1 "2026-04-15T13:31:02Z")
Hi Team, I am attempting to schedule a callback from my Zoom account using the API. I have prior experience working with Zoom APIs and have successfully executed multiple API calls in the past. However, I am currently facing an issue specifically with scheduling a callback. When I attempt to create a scheduled callback, I receive the following error response: ```auto { "code": 300, "message": "Invalid value for field 'null': invalid type" } ``` Based on the documentation, this error indicates that one of the fields in the request may have an incorrect format or data type. However, I have reviewed my request and believe it follows the required structure. Please find the request details below: **Endpoint:** [https://api.zoom.us/v2/contact\_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled\_callbacks/events](https://api.zoom.us/v2/contact_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled_callbacks/events) **Method:** POST **Content-Type:** application/json **Request Body:** ```auto { "start_time": "2026-04-17T15:00:00Z", "attendees": [ { "first_name": "Vignesh", "last_name": "Chellamani", "phone_number": "+916369748867", "email": "acvignesh22@gmail.com" } ] } ``` I am using the following Queue ID: ZWQC647829DDA8E5E9235F498C778157CEE Below are the details retrieved for this queue: ```auto { "queue_id": "ZWQC647829DDA8E5E9235F498C778157CEE", "cc_queue_id": "tbb85R2AT6aITy4hIpLwcw", "queue_name": "Zoomly Schedule Callback", "channel_types": [ "voice" ], "channel": "voice", "agents_count": 3, "supervisors_count": 0, "modified_by": "QIdCXmnhREmoPzqlZViALw", "last_modified_time": "2025-09-12T08:40:46Z" } ``` I have shared all the relevant details above for your reference. Could you please review my API request and confirm whether the request format or parameters are incorrect? Your assistance in resolving this issue would be greatly appreciated. Please let me know if any additional information is required. Thank you for your support. Best regards, Santhosh ---
**Author:** ![donte.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/donte.zoom/32/24412_2.png) [@donte.zoom](https://devforum.zoom.us/u/donte.zoom)\ **Post date:** [April 15, 2026, 5:43pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/2 "2026-04-15T17:43:43Z")
Thank you for posting, @Santhosh1 ! As a test, can you remove the plus sign (+) from the phone number and share the results? Also, I noticed you entered 12 digits. Is that the correct length for the country associated with that number? ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 16, 2026, 4:56am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/3 "2026-04-16T04:56:45Z")
Hi Dear, I attempted the API request again after removing the “+” symbol from the request body; however, I am still receiving the same response. Please find the API details below for your reference: **URL:** [https://api.zoom.us/v2/contact\_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled\_callbacks/events](https://api.zoom.us/v2/contact_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled_callbacks/events) **Request Body:** ```auto { "attendees": [ { "email": "cpbala4@gmail.com", "first_name": "Jill", "last_name": "Chill", "phone_number": "97144986467" } ], "start_time": "2026-04-17T15:00:00Z" } ``` **Response:** ```auto { "code": 300, "message": "Invalid value for field 'null': invalid type" } ``` I suspect the issue might be related to the **start\_time** format in the request body. Could you please confirm if the format I am using is correct? Additionally, I would appreciate it if you could perform a test API call from your end and share the results. I will replicate the same on my side for comparison. Looking forward to your guidance. ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 16, 2026, 5:16am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/4 "2026-04-16T05:16:06Z")
Also, I’m passing my UAE mobile number which is correct ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 17, 2026, 8:18am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/5 "2026-04-17T08:18:38Z")
Hi Zoom Team, Have we received any update on my request? I am following the steps mentioned in the Zoom API documentation; however, my API call is failing with a **300 status code**. I would appreciate your support in resolving this issue. ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 20, 2026, 9:12am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/6 "2026-04-20T09:12:49Z")
Hi Zoom Team, Requesting your support on the above matter. @donte.zoom @justin.steinberg Regards, Santhosh ---
**Author:** ![justin.steinberg](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/justin.steinberg/32/9988_2.png) [@justin.steinberg](https://devforum.zoom.us/u/justin.steinberg)\ **Post date:** [April 22, 2026, 8:22pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/7 "2026-04-22T20:22:47Z")
Hi @Santhosh1 I am checking on this issue for you and will share an update. ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 24, 2026, 9:48am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/8 "2026-04-24T09:48:18Z")
Thanks for the update @justin.steinberg Waiting for your response ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [April 30, 2026, 5:30am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/9 "2026-04-30T05:30:03Z")
Hi @justin.steinberg , Did we got any update? ---
**Author:** ![donte.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/donte.zoom/32/24412_2.png) [@donte.zoom](https://devforum.zoom.us/u/donte.zoom)\ **Post date:** [May 4, 2026, 3:36pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/10 "2026-05-04T15:36:30Z")
@Santhosh1 , Sorry for the delay—I needed to get an account enabled to properly test this. I was able to reproduce the behavior as described. I’ve created an internal ticket (ZSEE-202311) for further investigation and will share updates as soon as I have more details. In the meantime, let me know if you uncover anything additional on your end that could help with debugging. ---
**Author:** ![Pranjal.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/pranjal.zoom/32/73273_2.png) [@Pranjal.zoom](https://devforum.zoom.us/u/Pranjal.zoom)\ **Post date:** [May 4, 2026, 5:37pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/11 "2026-05-04T17:37:37Z")
Hi @Santhosh1 , Based on the current Zoom Contact Center API design for scheduling callbacks, your request body is structurally close, but the **error “Invalid value for field ‘null’: invalid type”** indicates that a required field or data type is missing or not recognized by the endpoint. Here’s how to correct and validate the call. * * * ### **✅ Correct Request Format** ```auto { "attendees": [ { "first_name": "Vignesh", "last_name": "Chellamani", "email": "XXXXXXXX@gmail.com", "phone_number": "+911234567890" } ], "start_time": "2026-04-17T15:00:00Z", "time_zone": "Asia/Kolkata", "language": "en-US", "callback_type": "voice", "source": "api", "notes": "Customer requested call between 3 PM–4 PM IST" } ``` **Endpoint:** ```auto POST https://api.zoom.us/v2/contact_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled_callbacks/events ``` ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 5, 2026, 4:36am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/12 "2026-05-05T04:36:37Z")
Hi @Pranjal.zoom Thank you for your response on this matter. We have tried using the exact request format you shared. Please find the details below: **Request Body:** ```auto { "attendees": [ { "first_name": "Vignesh", "last_name": "Chellamani", "email": "acvignesh22@gmail.com", "phone_number": "+911234567890" } ], "start_time": "2026-05-17T15:00:00Z", "time_zone": "Asia/Kolkata", "language": "en-US", "callback_type": "voice", "source": "api", "notes": "Customer requested call between 3 PM–4 PM IST" } ``` **Endpoint:** ```auto https://api.zoom.us/v2/contact_center/queues/ZWQC647829DDA8E5E9235F498C778157CEE/scheduled_callbacks/events ``` However, we are still encountering the same error: ```auto "code": 300, "message": "Invalid value for field 'null': invalid type" ``` Could you please confirm if there are any account-level settings that need to be enabled specifically for this API to function correctly? We have already reviewed the configuration on our end, and everything appears to be in order. Additionally, as Justin previously mentioned, could you please check if there might be any issue or bug associated with our account? We would appreciate your assistance in identifying the root cause and resolving this issue at the earliest. Looking forward to your response. ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 5, 2026, 4:37am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/13 "2026-05-05T04:37:41Z")
![Screenshot 2026-05-05 094927](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/5/b/5b5c91ed712c23d240f5de6dd3792820b6d45460.jpeg) @Pranjal.zoom Attached Screenshot for your reference ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 7, 2026, 4:51pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/14 "2026-05-07T16:51:06Z")
Dear Team, @donte.zoom @Pranjal.zoom @justin.steinberg We have been facing this issue for the past two weeks, and it is significantly affecting our business operations. Despite following the troubleshooting steps provided by your team, the API continues to fail. Could you please investigate this issue on priority and provide us with an update at the earliest? Thank you for your support. ---
**Author:** ![justin.steinberg](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/justin.steinberg/32/9988_2.png) [@justin.steinberg](https://devforum.zoom.us/u/justin.steinberg)\ **Post date:** [May 11, 2026, 12:06pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/15 "2026-05-11T12:06:18Z")
Hi @Santhosh1 this issue will be addressed this upcoming weekend as part of the ZCC May 2026 release. ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 14, 2026, 5:42pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/16 "2026-05-14T17:42:00Z")
@justin.steinberg Hi Justin, I have reviewed the May release notes for Zoom Contact Center, and there is no mention of a fix for this issue. Additionally, I tested the API call again to verify the current status, and I am still receiving the same error response with `"code": 300`. Could you please check this on priority and advise us on the correct approach to resolve the issue? ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 18, 2026, 5:17am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/17 "2026-05-18T05:17:03Z")
Hi @justin.steinberg @Pranjal.zoom @donte.zoom , We have raised another ticket through the Partner Portal, but we are still being advised to reach out to the Dev Forum for API-related queries. This callback API is widely used by many of our customers, and the current issue is blocking feature activation for several implementations. We require your support on priority and would appreciate guidance on the correct steps to resolve this issue. If needed, we are available to join a quick call to discuss this further. ---
**Author:** ![justin.steinberg](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/justin.steinberg/32/9988_2.png) [@justin.steinberg](https://devforum.zoom.us/u/justin.steinberg)\ **Post date:** [May 19, 2026, 8:59pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/18 "2026-05-19T20:59:17Z")
Hi @Santhosh1 the Scheduled Callback API should be resolved now, can you please check it again? ---
**Author:** ![Santhosh1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/santhosh1/32/74364_2.png) [@Santhosh1](https://devforum.zoom.us/u/Santhosh1)\ **Post date:** [May 23, 2026, 3:59am UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/19 "2026-05-23T03:59:31Z")
Hi @justin.steinberg It’s working now. Kindly implement a backup solution in case the same issue occurs in the future, as this issue significantly impacted our solution delivery to the customer. Thank you for your support. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/1/614bdd549b610bbaa46ff934617683a02bdaa03c.png) [@system](https://devforum.zoom.us/u/system)\ **Post date:** [November 3, 2026, 8:39pm UTC](https://devforum.zoom.us/t/issue-with-scheduling-callback-via-zoom-api/142993/20 "2026-11-03T20:39:32Z")
Closed on November 3, 2026, 8:39pm UTC This topic was automatically closed 24 hours after the last reply. New replies are no longer allowed.