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Documentation Index

Fetch the complete documentation index at: https://plivo.com/docs/llms.txt

Use this file to discover all available pages before exploring further.

  • What: Default rate limits, CPS caps, concurrent call thresholds, and feature limits for your Plivo account
  • Key defaults: Outbound CPS = 2, Inbound CPS = 10, max call duration = 4 hours, conference max = 20 participants
  • India-specific: Default concurrency limit of 50 concurrent calls. CPS = concurrency ÷ 25 (so 50 concurrent calls = 2 CPS)
  • API rate limit: 300 requests per 5 seconds for both call and non-call APIs
  • Short-duration limits: Abandoned calls (0s) and short calls (≤6s) capped at 20% of monthly volume each. Excess calls incur surcharges. India calls excluded.
  • To increase limits: Contact Plivo Sales. Requires minimum commitment
The Plivo features and components mentioned here have default limits. You can change them through our APIs or XML, or by contacting us.

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Understanding CPS vs Concurrent Calls

Two important concepts for voice call capacity:
TermDefinition
CPS (Calls Per Second)Rate at which new calls can be initiated
Concurrent CallsTotal number of calls active at the same time
Key difference: CPS limits how fast you can start calls. Concurrent calls is how many calls can be active simultaneously.

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Global (outside India)

Limit TypeDefaultNotes
Outbound CPS2Can be increased
Inbound CPS10Can be increased
Concurrent CallsNo limitOnly CPS limits apply

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India

India has additional concurrency limits. Calls that exceed the limit are rejected immediately with error code 5030 (Concurrency Limit Breached).
Limit TypeDefaultCalculation
Concurrent Calls50Concurrency limit (default 50)
Outbound CPS2Concurrency limit ÷ 25
Hard enforcement is active from April 20, 2026. Calls exceeding the concurrency limit fail instantly with no queuing or grace period. If your 30-day peak usage exceeds 80% of your limit, increase your concurrency limit before experiencing call failures.
For a full guide on how concurrency is calculated, what counts as a concurrent call, how to check your usage, and how to increase your limit, see India Concurrency Limits. To increase your concurrency or CPS limits, raise a ticket with Plivo support.

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Outbound Call API limits

By default, all accounts come with a limit of two calls per second. All outbound Call API requests are queued upon acceptance, then dequeued and initiated as per the calls per second (CPS) configured for your Plivo account.

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SIP/browser calls and inbound calls to Plivo numbers

Inbound CPS refers to the limitation on outbound calls from SIP and browser clients and inbound calls to Plivo numbers. (These are all called Inbound CPS because outgoing call requests from SIP and browser clients are also inbound requests to Plivo.) The default Inbound CPS limit is 10. Here are three scenarios that show how Inbound CPS limits might apply. In all three, only 10 calls per second will be processed; the rest will be rejected. Scenario 1 Outbound SIP/browser calls: 11 calls
Inbound calls to Plivo numbers: 0 calls Scenario 2 Outbound SIP/browser calls: 0 calls
Inbound calls to Plivo numbers: 11 calls Scenario 3 Outbound SIP/browser calls: 5 calls
Inbound calls to Plivo numbers: 6 calls

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Make-call API limits

By default, Plivo limits all accounts to 300 API requests per five seconds. This limit is for below APIs:
  • Make an Outbound Call API
  • Add a Participant to a multiparty call using API
If you send more requests than the specified limit in the specified duration, Plivo will block the requests and respond with the HTTP error 429 Too Many Requests. If you see this error, throttle your API requests and retry

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Non-call API limits

By default, Plivo limits all accounts to 300 API requests per five seconds. This limit is for all APIs excluding those that initiate a call:
  • All Call APIs (except “initiate a call”)
  • All Recording APIs
  • All Conference APIs
  • All Endpoint APIs
  • All Application APIs
If you send more non-call requests than the specified limit in the specified duration, Plivo will block the requests and respond with the HTTP error 429 Too Many Requests. If you see this error, throttle your API requests and retry. Note: You can increase your account’s CPS or the rate of non-call API requests, but because doing so incurs extra costs on the part of carriers and server providers, Plivo requires a minimum commitment, the level of which depends on the rate of calls per second or non-call API requests you want. Please contact our sales team to discuss your situation.

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Feature-level limits

In addition to the account-level limits, Plivo has some feature-level limits.

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Time limit for calls

The default maximum duration for outbound and inbound calls connected using Make a Call API and Dial XML is four hours starting from the time a call is answered. You can extend the limit to 86,400 seconds (24 hours).

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Call recordings

By default, the maximum duration for call recordings is 60 seconds. For calls that you record using Record API or Record XML, the maximum recording duration is 24 hours.

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Conference calls

Two limits have to do with conference calls.
  • Participants: You can have a maximum of 20 participants in a conference room. You can set the maxMembers to be between 1 to 20.
  • Duration: The maximum duration for a conference is 86,400 seconds (24 hours). A conference call will get disconnected after 24 hours.
Refer to the Conference XML element reference page for details.

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Voice transcriptions

You can transcribe a call using the Record API, Record Conference API, Record XML, and Conference XML.
  • Duration: Our transcription service is limited to calls with a duration greater than 5 seconds and less than four hours.
  • Recording file size: The maximum recording file size is 2GB.

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Abandoned and short-duration call thresholds

Plivo enforces monthly limits on the proportion of abandoned and short-duration calls in your traffic. When the percentage of these calls exceeds the threshold, a per-call surcharge applies to the excess calls.
Call typeMonthly thresholdSurcharge on excess calls
Abandoned calls (0 seconds)20%$0.005 per excess call
Short calls (≤6 seconds)20%$0.0025 per excess call
These limits apply to both Voice API and SIP Trunking calls.
Calls to India are excluded from these thresholds and surcharges. The 20% limit and per-call charges apply only to non-India destinations.