Account Limits


    In this guide, we will show you the various account limits that are related to the different features and components on the Plivo Voice platform. These limits have default values, and you can change them by contacting us as per your requirements. This guide explains the limitations and the process of changing them.


    There are two limitations concerning rate-limiting on the Voice platform.

    1. Account-level limitations on the number of calls allowed per second.
    2. Account-level limitations on the number of non-call API requests per 5 seconds.

    See the following sections to understand more about these limits.

    Outbound API Calls

    By default, all accounts come with a limit of 2 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.

    SIP/Browser Calls & Inbound Calls to Plivo Numbers

    Inbound CPS refers to the limitation on outbound calls from SIP/Browser clients and the inbound calls to Plivo numbers. (This is termed as Inbound CPS as outgoing call requests from SIP/Browser Clients are also inbound requests to Plivo.) The default Inbound CPS is 10.

    Let’s consider different scenarios of how this Inbound CPS will be applicable:In all three scenarios below, only 10 calls will be processed and the rest will be rejected.

    1. Scenario 1:
      1. Outbound SIP/Browser Calls: 11 calls
      2. Inbound Calls to Plivo Numbers: 0 calls.
    2. Scenario 2:
      1. Outbound SIP/Browser Calls: 0 calls
      2. Inbound Calls to Plivo Numbers: 11 calls.
    3. Scenario 3:
      1. Outbound SIP/Browser Calls: 5 calls
      2. Inbound Calls to Plivo Numbers: 6 calls.

    Non-Call APIs

    By default, all accounts come with a limit of 300 API requests per 5 seconds. This limit is for the APIs excluding any that “initiate a call”. If you send more non-call requests than the specified limit in the specified duration, then Plivo will block those requests and respond with an HTTP error “429 Too Many Requests”. You can throttle your API requests so that you don’t receive these 429 errors and if you do get this error, it’s safe to retry.

    The following Voice APIs are included under this limit:

    • All Call APIs (except “Initiate a call”)
    • All Recording APIs
    • All Conference APIs
    • All Endpoint APIs
    • All Application APIs
    Note: If you wish to increase your account CPS or the number of non-call API requests for your account, please send us a message on the Contact Page. (Due to extra costs incurred by carriers and server providers, a minimum commitment is required, depending on the number of calls per second or the non-call API requests per 5 seconds you request).

    Feature-level Limits

    In addition to the account-level limits, below are some feature-level limits. We will walk you through these limits in this section that will help you to implement the voice related features into your apps hassle-free.

    Time-limit for Calls

    This limit is related to the maximum duration for all the calls connected on the Plivo Voice platform, both outbound and inbound calls have a default limit of 4 hours. Time-limit is calculated starting from the time the call is answered. This limitation is applicable for the calls connected using Make a Call API and Dial XML. By default, the time limit is 14,400 seconds (4 hours), and you can extend it to 86,400 seconds (24 hours). The call will get disconnected once the time specified in the timeLimit attribute has been reached.

    Call Recordings

    This limit is related to the maximum duration for call recordings. By default, this limit is 60 seconds. For any calls that you record using Record API, Record XML, or the record attribute of the Conference XML, the maximum recording duration is 24 hours.

    Conference Calls

    There are a couple of limits with the conference calls, such as maxMembers and timeLimit.

    • Max Members: You can have a maximum of 20 participants in a conference room. You can set the maxMembers to be between 1 to 20.
    • Time Limit: The maximum duration allowed for a conference room is 86, 400 seconds (24 hours). The conference call will get disconnected after 24 hours.

    You can refer to the Conference XML reference for more details.

    Voice Transcriptions

    You can transcribe a call using the Record API, Record Conference API, Record XML, & Conference XML. The limitations specific to the voice transcriptions are such as the language-supported, maximum recording duration & recording file size.

    • Language-support: Currently, this service is available only in English.
    • Recording Duration: Our transcription service is limited to calls with a call duration greater than 500 milliseconds and less than 4hours.
    • Recording File Size: The maximum recording file size is 2GB.