generated: '2026-08-27'
method: searched
source: https://signalwire.com/docs/platform/rate-limits
docs: https://signalwire.com/docs/platform/rate-limits
note: >-
  SignalWire publishes account-level throughput limits that count activity across every Project in a
  Space, plus a separate API request limit. Voice and Messaging limits are independent — exceeding
  one does not queue the other. Over-rate traffic is QUEUED rather than rejected, up to a backlog
  ceiling. The docs say "Every HTTP request includes the user's current limit and remaining requests
  in its X-Header" but do NOT name the header keys, so no header names are recorded here rather than
  guessed at; an agent should read whatever X-RateLimit-style headers the response carries.
limit_count: 10
response_headers:
  documented: true
  header_names_published: false
  statement: Every HTTP request includes the user's current limit and remaining requests in its X-Header.
  exhaustion_status: 429
  exhaustion_note: 429 Too Many Requests is documented in the error-code reference as "you've exceeded
    a rate limit. Back off and retry."
  retry_after: unknown
limits:
- name: API writes
  scope: per-account (all Projects in a Space)
  applies_to: POST, PUT, PATCH across the SignalWire platform
  limit: 13800
  window: 10 seconds
  burst: null
- name: API reads
  scope: per-account (all Projects in a Space)
  applies_to: GET, DELETE across the SignalWire platform
  limit: null
  window: null
  note: Documented as "effectively unlimited".
- name: Outbound calls
  scope: per-account
  applies_to: Voice (and Fax, which is sent over phone calls)
  limit: 1
  window: 1 second
  unit: calls per second (CPS)
  increase: Contact Support / Space Increase Request Form
- name: Messaging — toll-free
  scope: per-account
  applies_to: SMS/MMS from toll-free numbers
  limit: 3
  window: 1 second
  unit: messages per second (MPS)
- name: Messaging — US long code (10DLC)
  scope: per-account
  applies_to: SMS/MMS from US 10DLC numbers
  limit: 4
  window: 1 second
  unit: messages per second (MPS)
  note: Actual throughput may be lower or higher depending on carrier and TCR (Campaign Registry) limits.
- name: Messaging — Canadian long code
  scope: per-account
  applies_to: SMS/MMS from Canadian long code numbers
  limit: 1
  window: 1 second
  unit: messages per second (MPS)
- name: Messaging — short code
  scope: per-account
  applies_to: SMS/MMS from short codes
  limit: 10
  window: 1 second
  unit: messages per second (MPS)
- name: Voice backlog
  scope: per-account
  applies_to: queued outbound calls
  limit: 10000
  window: null
  unit: queued calls
  note: When the backlog is full SignalWire stops adding calls to the Voice queue.
- name: Messaging backlog
  scope: per-account
  applies_to: queued outbound messages
  limit: 10000
  window: null
  unit: queued messages
  note: Separate from the Voice backlog.
- name: Phone numbers per Project
  scope: per-project
  applies_to: provisioned phone numbers
  limit: 1000
  window: null
  note: >-
    Space limit, applies to Spaces not in Trial mode. Requests above 1000 require additional
    verification and auto top-up configured to the monthly cost of the numbers.
queueing:
  behavior: >-
    Traffic above the applicable rate is queued in the order received and processed at the maximum
    applicable rate; new work is accepted while the backlog has capacity.
  voice_backlog: 10000
  messaging_backlog: 10000
  independent: true
increase_process:
  form: https://forms.signalwire.me/Space-Increase-Request.html
  support: https://support.signalwire.com/portal/en/newticket
  reviewer: SignalWire Space Compliance team
  note: Message segments each count toward the MPS limit; large messages are split into segments.
trial_mode:
  note: New accounts remain in Trial mode until at least $5 USD of credit is added; Space limits above
    apply to Spaces not in Trial mode.