​ To learn more, see the sources I considered: [[1] Discord message from @cartier5 on 2025-02-21](https://discord.com/channels/1186424376300679209/1186462578310910112/1342534237789618368) [[2] Concurrent calls per account](https://discord.com/channels/1186424376300679209/1376989546629300286) [[3] Understand concurrency & limits](https://docs.retellai.com/deploy/concurrency) ​

### Answer Concurrency limits in Retell AI are per account (workspace) , not per agent or phone number. [(1) ]() [(2) ]() When building AI agents for multiple clients on a single account, you'll face these key constraints: Concurrency Limitations: - Pay-As-You-Go users get a default quota of 20 concurrent calls [(3) ]() - This limit applies across all agents in your account [(2) ]() - If you have 6 agents, those 6 agents together can only make 20 calls simultaneously, not 20 calls each - Each agent can handle unlimited calls, provided total concurrency stays within your quota [(3) ]() Potential Problems: - Shared Resources: All clients share the same 20-call concurrency pool, so one client's high call volume can block another client's calls [(3) ]() [(2) ]() - Scaling Costs: Additional concurrency costs $8 per concurrent call to increase your limit - Data Separation: You'd need to carefully manage which calls belong to which client since they're all in one account Better Architecture: Consider creating separate workspaces for each client. [(2) ]() This allows you to: - Send invites to each client for their workspace - Ensure clients only see calls in their workspace - However, concurrency is still shared across your account, so you'd still need to purchase more if needed Burst Capacity: Retell offers Concurrency Burst which al

lows temporary spikes up to 3× your limit (or limit + 300, whichever is lower) with a $0.10/min surcharge. [(3) ]()

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.