Hi Smith (hasbulla),
For inbound calls, Vapi does impose a concurrency limit of 10 simultaneous calls for inbound and outbound calls combined. This is the primary restriction. There is no cap on the total number of inbound calls you can receive over time, but incoming calls beyond the concurrent limit will queue or be rejected until slots free up.
As far as outbound limits, we impose these limits only on our free numbers as they are mainly for testing out your integrations. Once you are ready to scale up, you can purchase a Twilio or Telnyx number that you can import into VAPI, which has less limitations for outbound.
If you need to handle more simultaneous calls, you can purchase additional concurrent lines through your billing dashboard [here](
https://docs.vapi.ai/billing/billing-limits).
For more details, you can refer to the [Billing Limits documentation](
https://docs.vapi.ai/billing/billing-limits).