Skip to main content
Concurrency is the maximum number of live calls your account can hold at the same time. Every active conversation - inbound or outbound - occupies exactly one channel. It caps how many calls run at once, not how fast new ones start; that second limit is CPS. Open it from Capacity → Concurrency in the left sidebar.
Concurrent Calls page with a Purchase Concurrent Calls card showing a quantity stepper in blocks of ten, an estimated monthly cost, a pricing bracket table with units, price per unit and subtotal, and a Buy Concurrent Calls button, beside a What is Concurrency explainer card describing simultaneous active channels and when to increase them

Concurrent Calls - purchase panel and explainer

​
When to raise concurrency

Once you hit the concurrency ceiling, new callers receive a busy signal. Scale it to match contact-centre headcount or campaign volume - one channel per agent or per simultaneous outbound leg, plus headroom for peaks. Inbound traffic is the case to watch: a busy signal is invisible in your own logs but very visible to the customer who got it. Check live utilisation against the ceiling with the Concurrency API, which returns concurrent_calls, max_concurrent, and utilization_pct.

​
Buying capacity

Capacity is purchased in blocks of 10 and billed monthly. The first month is charged on purchase, and the subscription then renews on its own cycle until you cancel it from My Subscriptions.
The prices in the screenshot belong to one account’s pricing tier. Your own rate appears in the bracket table as you change the quantity, and Preview capacity pricing returns the same figure over the API without charging anything.

​
Buy it over the API

Preview capacity pricing

Calculate the monthly price for a concurrency quantity without creating a subscription.

Purchase capacity

Create the subscription with resource_type: "concurrent_calls" and a quantity.

Check live concurrency

Read current channel usage and headroom in real time.