---
title: "Start verification"
method: POST
path: "/verification/v1/verifications"
tags: ["Verifications start"]
---

# Start verification

`POST /verification/v1/verifications`

This method is used by the mobile and web Verification SDKs to start a verification. It can also be used to request a verification from your backend, by making an request.

## Headers

- `Accept-Language` string

## Request body

- union
  - VerificationStartRequestBase
    - `identity` Identity, required — Specifies the type of endpoint that will be verified and the particular endpoint. `number` is currently the only supported endpoint type.
      - `type` 'number', required — Currently only `number` type is supported.
      - `endpoint` string, required — For type `number` use an [E.164](https://community.sinch.com/t5/Glossary/E-164/ta-p/7537)-compatible phone number.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `reference` string — Used to pass your own reference in the request for tracking purposes. Must be a unique value for each started verification request. The value must be encodable in the URL path segment. This value is passed to all events and returned from the status and report endpoints. The reference can be used to check the [status of verifications](https://developers.sinch.com/docs/verification/api-reference/verification/verification-status/verificationstatusbyreference), like with ID or identity.
    - `custom` string — Can be used to pass custom data in the request. Will be passed to all events. Max length 4096 characters, can be arbitrary text data.
  - object
    - `identity` Identity, required — Specifies the type of endpoint that will be verified and the particular endpoint. `number` is currently the only supported endpoint type.
      - `type` 'number', required — Currently only `number` type is supported.
      - `endpoint` string, required — For type `number` use an [E.164](https://community.sinch.com/t5/Glossary/E-164/ta-p/7537)-compatible phone number.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `reference` string — Used to pass your own reference in the request for tracking purposes. Must be a unique value for each started verification request. The value must be encodable in the URL path segment. This value is passed to all events and returned from the status and report endpoints. The reference can be used to check the [status of verifications](https://developers.sinch.com/docs/verification/api-reference/verification/verification-status/verificationstatusbyreference), like with ID or identity.
    - `custom` string — Can be used to pass custom data in the request. Will be passed to all events. Max length 4096 characters, can be arbitrary text data.
    - `flashCallOptions` object — An optional configuration for Flash Call Verification, should be used only when the verification request originates from your backend (not an end user device) and request is signed via an [Application signed request](https://developers.sinch.com/docs/voice/api-reference/authentication/signed-request).
      - `dialTimeout` integer — The amount of time that a phone will ring.
      - `interceptionTimeout` integer — The maximum time that a phone call verification will be active and can be completed. If the phone number hasn't been verified successfully during this time, then the verification request will fail. By default, the Sinch dashboard will automatically optimize dial time out during a phone call.
  - object
    - `identity` Identity, required — Specifies the type of endpoint that will be verified and the particular endpoint. `number` is currently the only supported endpoint type.
      - `type` 'number', required — Currently only `number` type is supported.
      - `endpoint` string, required — For type `number` use an [E.164](https://community.sinch.com/t5/Glossary/E-164/ta-p/7537)-compatible phone number.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `reference` string — Used to pass your own reference in the request for tracking purposes. Must be a unique value for each started verification request. The value must be encodable in the URL path segment. This value is passed to all events and returned from the status and report endpoints. The reference can be used to check the [status of verifications](https://developers.sinch.com/docs/verification/api-reference/verification/verification-status/verificationstatusbyreference), like with ID or identity.
    - `custom` string — Can be used to pass custom data in the request. Will be passed to all events. Max length 4096 characters, can be arbitrary text data.
    - `calloutOptions` object — An optional configuration for Phone Call Verification, should be used only when the verification request originates from your backend (not an end user device) and request is signed via an [Application signed request](https://developers.sinch.com/docs/voice/api-reference/authentication/signed-request).
      - `speech` PhoneCallSpeech — Text-To-Speech engine settings
        - `locale` string — A `language-region` identifier according to [IANA](https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry). Only a subset of those identifiers is accepted.
  - object
    - `identity` Identity, required — Specifies the type of endpoint that will be verified and the particular endpoint. `number` is currently the only supported endpoint type.
      - `type` 'number', required — Currently only `number` type is supported.
      - `endpoint` string, required — For type `number` use an [E.164](https://community.sinch.com/t5/Glossary/E-164/ta-p/7537)-compatible phone number.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `reference` string — Used to pass your own reference in the request for tracking purposes. Must be a unique value for each started verification request. The value must be encodable in the URL path segment. This value is passed to all events and returned from the status and report endpoints. The reference can be used to check the [status of verifications](https://developers.sinch.com/docs/verification/api-reference/verification/verification-status/verificationstatusbyreference), like with ID or identity.
    - `custom` string — Can be used to pass custom data in the request. Will be passed to all events. Max length 4096 characters, can be arbitrary text data.
    - `smsOptions` object — An optional configuration for Sms Verification, should be used only when the verification request originates from your backend (not an end user device) and request is signed via an [Application signed request](https://developers.sinch.com/docs/voice/api-reference/authentication/signed-request).
      - `codeType` 'Numeric' | 'Alpha' | 'Alphanumeric' — Selects type of code which will be sent to customer
      - `expiry` string — The expiration time for a verification process is represented in the format `HH:MM:SS`.
  - object
    - `identity` Identity, required — Specifies the type of endpoint that will be verified and the particular endpoint. `number` is currently the only supported endpoint type.
      - `type` 'number', required — Currently only `number` type is supported.
      - `endpoint` string, required — For type `number` use an [E.164](https://community.sinch.com/t5/Glossary/E-164/ta-p/7537)-compatible phone number.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `reference` string — Used to pass your own reference in the request for tracking purposes. Must be a unique value for each started verification request. The value must be encodable in the URL path segment. This value is passed to all events and returned from the status and report endpoints. The reference can be used to check the [status of verifications](https://developers.sinch.com/docs/verification/api-reference/verification/verification-status/verificationstatusbyreference), like with ID or identity.
    - `custom` string — Can be used to pass custom data in the request. Will be passed to all events. Max length 4096 characters, can be arbitrary text data.
    - `whatsappOptions` object — An optional configuration for WhatsApp Verification, should be used only when the verification request originates from your backend (not an end user device) and request is signed via an [Application signed request](/docs/voice/api-reference/authentication/signed-request).
      - `codeType` 'Numeric' | 'Alpha' | 'Alphanumeric' — Selects type of code which will be sent to customer

## Response `200`

A success response, or an [Error](https://developers.sinch.com/docs/verification/api-reference/errors/).

- union
  - object
    - `id` string, required — Verification identifier used to query for status.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `_links` Links[]
      - `rel` 'status' | 'report' — The related action that can be performed on the initiated Verification.
      - `href` string — The complete URL to perform the specified action, localized to the DataCenter which handled the original Verification request.
      - `method` string — The HTTP method to use when performing the action using the linked localized URL.
    - `sms` object — The response contains the `template` of the SMS to be expected and intercepted.
      - `template` string — The expected template for the SMS response.
      - `interceptionTimeout` integer — The amount of time in seconds that the client should wait for the SMS.
      - `codeType` 'Numeric' | 'Alpha' | 'Alphanumeric' — Selects type of code which will be sent to customer
  - object
    - `id` string, required — Verification identifier used to query for status.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `_links` Links[]
      - `rel` 'status' | 'report' — The related action that can be performed on the initiated Verification.
      - `href` string — The complete URL to perform the specified action, localized to the DataCenter which handled the original Verification request.
      - `method` string — The HTTP method to use when performing the action using the linked localized URL.
    - `flashCall` object — The response contains the `cliFilter` and `interceptionTimeout` properties.
      - `cliFilter` string, required — Filter that should be applied for incoming calls to intercept the flash call.
      - `interceptionTimeout` integer, required — Amount of seconds client should wait for the flash call.
      - `reportTimeout` integer — The time in seconds allowed for reporting the code after which the verification will expire.
      - `denyCallAfter` integer — Used by the mobile SDKs, this setting makes the handset deny the flash call after the set time in seconds.
  - VerificationStartResponseBase
    - `id` string, required — Verification identifier used to query for status.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `_links` Links[]
      - `rel` 'status' | 'report' — The related action that can be performed on the initiated Verification.
      - `href` string — The complete URL to perform the specified action, localized to the DataCenter which handled the original Verification request.
      - `method` string — The HTTP method to use when performing the action using the linked localized URL.
  - object
    - `id` string, required — Verification identifier used to query for status.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `_links` Links[]
      - `rel` 'status' | 'report' — The related action that can be performed on the initiated Verification.
      - `href` string — The complete URL to perform the specified action, localized to the DataCenter which handled the original Verification request.
      - `method` string — The HTTP method to use when performing the action using the linked localized URL.
    - `seamless` object, required — The response contains the target URI.
      - `targetUri` string — The target URI.
  - object
    - `id` string, required — Verification identifier used to query for status.
    - `method` 'sms' | 'flashcall' | 'callout' | 'seamless' | 'whatsapp', required — The type of the verification request.
    - `_links` Links[]
      - `rel` 'status' | 'report' — The related action that can be performed on the initiated Verification.
      - `href` string — The complete URL to perform the specified action, localized to the DataCenter which handled the original Verification request.
      - `method` string — The HTTP method to use when performing the action using the linked localized URL.
    - `whatsapp` object — The response contains the `codeType` property.
      - `codeType` 'Numeric' | 'Alpha' | 'Alphanumeric' — Selects type of code which will be sent to customer

---

[API](https://skmtc.net/sinch/apis/verification-sinch.md) · [All operations](https://skmtc.net/sinch/apis/verification-sinch/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sinch/verification-sinch/revisions/bbeffc72789a/schema)