# Rate limits The below throughput limits apply to Voice and Messaging. These are account-level limits that count activity from all Projects within your Space. Contact Support to [increase a Spaces default limits][1], and [contact Sales][3] to increase Voice and Messaging throughput. :::tip separate limits Rate limits and backlogs for Messaging and Voice are separate. For example, exceeding the Voice rate limit does ***not*** cause outbound messages to [queue](#queue-and-backlog-system). ::: ## Voice [View pricing](https://signalwire.com/pricing/voice) and [contact Sales][3] to increase calling throughput. | Value | Default limit | | :-- | : | | Calls | 1 call per second (CPS) | | [Backlog](#queue-and-backlog-system) | 10,000 queued calls | ## Messaging [View pricing][2] and [contact Sales][3] to increase messaging throughput for toll-free or short code numbers. | Number type | Default limit | | :-- | :- | | Toll-free | 3 messages per second (MPS) | | US long code (10DLC) | 4 MPS
Actual throughput may be lower or higher depending on carrier and [TCR](/guides/campaign-registry-all-you-need-to-know) limits | | Canadian long code | 1 MPS | | Short code | 10 MPS | | [Backlog](#queue-and-backlog-system) | 10,000 queued messages | :::warning segments count as messages Larger messages are automatically split into smaller segments which are sent as individual messages. Each of these segments counts towards the messages per second (MPS) limit. Consult the guide to [Messaging Character Limits](/guides/messaging-character-limits) for more information. ::: ## API The below limits apply to all API requests across the SignalWire platform. Every HTTP request includes the users current limit and remaining requests in its X-Header. | HTTP verb | Limit | | :- | :-- | | GET DELETE | Effectively unlimited | | POST PUT PATCH | 13800 requests per 10 seconds | ## Queue and backlog system When an application sends calls or messages to SignalWire at a rate exceeding the applicable rate limit, SignalWire **queues** these messages or calls in the order received. The **backlog** is the limit to the number of queued (pending) calls or messages. The Voice backlog and Messaging backlog are both 10,000 by default. When the backlog for calls is full, SignalWire will stop adding additional calls to the Voice queue. Similarly, when the backlog for messages is full, SignalWire will stop adding to the Messaging queue. The platform will process queued calls or messages at the maximum applicable rate, and add new calls or messages to the queue as long as the backlog has not been reached. :::info separate backlogs The Voice and Messaging backlogs are entirely separate. ::: If you would like to raise your Voice or Messaging backlog, [request an increase to your Space limits][1]. [1]: /guides/how-to-request-an-increase-to-your-signalwire-space-limits (Request an increase to Space limits) [2]: https://signalwire.com/products/cloud-messaging/high-throughput-messaging (Pricing and other information about high-throughput messaging) [3]: https://signalwire.com/company/contact (Contact Sales)