# Error when trying to use Webinar registration API **URL:** \ **Category:** API and Webhooks\ **Created:** [June 12, 2020, 4:11pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207 "2020-06-12T16:11:49Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![zoommeeting](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/zoommeeting/32/18751_2.png) [@zoommeeting](https://devforum.zoom.us/u/zoommeeting)\ **Post date:** [June 12, 2020, 4:11pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207/1 "2020-06-12T16:11:49Z")
I set up a series of webinars and use the registration API to allow attendees to “Register for All”. All webinars are set up as on-demand. API works fine until the day _after_ the live webcast. From then on an error saying that you can’t register for a past webinar is issued. BUT, because the webinar is on demand, if I manually use the registration link it works fine and I can view the webinar recording. Why does the API throw an error and what (if anything) can I do about it? Specific API being used is POST /webinars/{webinarId}/registrants ---
**Author:** ![michael.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael.zoom/32/37213_2.png) [@michael.zoom](https://devforum.zoom.us/u/michael.zoom)\ **Post date:** [June 17, 2020, 8:55pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207/2 "2020-06-17T20:55:42Z")
Hi @zoommeeting, I understand what you’re trying to do with the instant webinar registration; however, the registration for occurrences might not be matching your use case. Are you trying to add a new registrant so they can view the recorded file? If this is the case, I would suggest providing the Play URL from the [Cloud Recordings API](https://marketplace.zoom.us/docs/api-reference/zoom-api/cloud-recording/recordingget). ---
**Author:** ![zoommeeting](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/zoommeeting/32/18751_2.png) [@zoommeeting](https://devforum.zoom.us/u/zoommeeting)\ **Post date:** [June 19, 2020, 8:23pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207/3 "2020-06-19T20:23:44Z")
I am aware that I could do that. It doesn’t really help as I’m not trying to allow them to play an individual webinar. That already works. I’d like to understand why what I’m doing doesn’t work. If the exact same webinar can be invoked from the exact same link as was used _prior_ to the live broadcast - why does the API throw an error? Has the link been preserved but under the covers the webinar Id has been changed? Not only that but why does the API registration fail the next day? On the day of the webinar it works - even though the webinar has ended. ---
**Author:** ![tommy](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/tommy/32/72769_2.png) [@tommy](https://devforum.zoom.us/u/tommy)\ **Post date:** [June 23, 2020, 8:41pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207/4 "2020-06-23T20:41:49Z")
Hey @zoommeeting, I believe you want to use the [Create a Recording Registrant API](https://marketplace.zoom.us/docs/api-reference/zoom-api/cloud-recording/meetingrecordingregistrantcreate). 🙂 Thanks, Tommy ---
**Author:** ![DeveloperBot](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/developerbot/32/12632_2.png) [@DeveloperBot](https://devforum.zoom.us/u/DeveloperBot)\ **Post date:** [August 21, 2020, 10:24pm UTC](https://devforum.zoom.us/t/error-when-trying-to-use-webinar-registration-api/21207/5 "2020-08-21T22:24:37Z")
Closed on August 21, 2020, 10:24pm UTC