Last_name is required when adding Registrant

Using this template helps us debug your issues more effectively :slight_smile:

A clear and concise description of what the question is.
Error given Last_name is required when adding Registrant. Why suddenly Last_name is mandatory? We don’t encounter such issue until 19 Dec 2021. I checked that there is no changes on the API at

The full error message or issue you are running into.
“{“code”:300,“message”:“The parameter is required: last_name.”}”

Which App Type (OAuth / Chatbot / JWT / Webhook)?
Knowing the endpoint/s can help us to identify your issue faster. Please link the ones you need help/have a question with.

Which Endpoint/s?
Knowing the API endpoint/s can help us to identify your issue faster. Please link the ones you need help/have a question with.{meetingid}/registrants

How To Reproduce (If applicable)
Steps to reproduce the behavior:

  1. Request URL / Headers (without credentials) / Body
  2. See error

Screenshots (If applicable)
If applicable, add screenshots to help explain your problem.

Additional context
Add any other context about the problem here.

Hi We Facing same issue while start meeting we getting

"StatusCodeError: 400 - {\\\“code\\\”:300,\\\“message\\\”:\\\"The parameter is required: last_name.\

same here, suddenly last_name is required field when registering new attendees.

Exact same issue. Is this being worked on? Is there an ETA on a fix? Or is this a breaking change that wasn’t communicated? Thanks!

Same issue here, we had to deploy an emergency fix over the weekend because of the unannounced change. Please alert us to breaking changes in advance

Hi All,

Thank you for your patience; our team is looking into this right now. It seems like a breaking change related to some updates. Take a look here:

Ctrl+F for “last name” to see the affected endpoints.


@gianni.zoom Can you please confirm if this getting fixed or we need to modify our integration? This is breaking our entire production registration process.

1 Like

We agree with pkarthik2391. Please confirm if you will be fixing this or not. In our case we were using a space (’ ') for the last_name, and now we are experiencing the error. Our production servers were affected, so we have temporarily replaced ’ ’ with ‘さん’ .

@gianni.zoom Merry Christmas. Could you please help here with an update?

Hi all,

This bug is still in progress for a fix. The ticket is ZOOM-333487 and we hope to have updates soon!

Thank you,

Hi All,

So this has been identified as a breaking change and going forward last_name will continue to be required for these endpoints.

Zoom will be more proactive about being more clear about breaking changes going forward to preserve the efforts of all of you using our APIs.

Thank you,

Here, too, the last-name field is suddenly needed when registering a new visitor. If you would like to attend a meeting anonymously on Zoom, join the meeting without logging in to your account. When you join a meeting as a guest, Zoom asks for your name. And you can enter any of your names. You can even become a Wizard of Oz, or Mr.