We just can't accept/make calls anymore? Does the called get some kind of error message? or does his call just not work?

@Fire either you can add a delay after every api call or else you have to upgrade your vapi's pricing plan inorder to increase the concurrent calls limit

Thanks @Richard but this is not my question tho. I am asking if for example I am allowed 10 concurrent calls, and there are ongoing 10 calls atm. If an 11th person calls my assistant, what exactly happens? Does the call connect and he gets an error message from vapi? does the call not connect in the first place?

If you are currently maxing out your concurrency and you get another call, you will get an error on your server URL but the user who is calling in will not hear a message or receive any notification from us on the reason the call is not being completed.