specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: Sinch Verification API
providerId: sinch-verify
created: '2026-07-11'
modified: '2026-07-11'
reconciled: false
tags:
- Number Verification
- OTP
- 2FA
- Rate Limiting
- Quotas
description: >-
  Sinch does not publish a single fixed numeric request-rate limit for the
  Verification API in its public documentation. In practice, throughput and
  abuse controls are governed at the application/account level and by
  per-number velocity limits designed to prevent verification fraud and
  pumping - for example, capping how frequently the same phone number can be
  re-verified within a time window. Some of these safeguards are configurable
  in the Sinch Build dashboard (velocity rules, allowed methods, country
  rules). Numeric per-endpoint limits are not documented as of the review date.
notes: >-
  Treat rate limiting as account- and number-scoped rather than a global
  per-second cap. Implement exponential backoff with jitter, honor any
  Retry-After header, and configure velocity/anti-fraud rules in the dashboard.
  Confirm exact limits with Sinch support during reconciliation.
sources:
- https://developers.sinch.com/docs/verification/introduction
- https://developers.sinch.com/docs/verification/api-reference/verification
- https://sinch.com/verification-api/
responseCodes:
  throttled: 429
limits:
- name: Verification API Requests
  scope: application
  metric: requests
  limit: not published
  notes: No fixed numeric per-second request-rate limit is documented publicly.
- name: Per-Number Velocity
  scope: number
  metric: verifications
  limit: configurable
  notes: Anti-fraud velocity limits cap how often the same number can be verified within a window; configurable via dashboard rules.
- name: Method / Country Rules
  scope: account
  metric: verifications
  limit: configurable
  notes: Allowed methods and destination countries can be restricted per application to control spend and abuse.
policies:
- name: Anti-Fraud Controls
  description: Velocity limits and rules mitigate verification pumping and SMS fraud; tune them in the Build dashboard.
- name: Backoff Strategy
  description: Clients should implement exponential backoff with jitter and honor Retry-After on 429 responses.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com