KYC Verification
Overview
Know Your Customer (KYC) verification is a regulatory requirement for processing payouts. It ensures that users receiving funds are properly identified and comply with anti-money laundering (AML) regulations.
All users must complete KYC verification before receiving their first payout. Coinflow offers multiple KYC verification methods to accommodate different merchant needs and existing KYC infrastructure.
Choosing Your KYC Method
Fastest integration - no setup required
- Best for: Most merchants, fastest time to market
- Setup time: Minutes (just call the API)
- User experience: Instant verification for US users, ID upload for international
- Maintenance: Coinflow handles all compliance updates
- Cost: Included in Coinflow’s payout fees
✅ Recommended for new integrations
Reuse your existing KYC data
- Best for: Merchants with established KYC providers
- Setup time: 2-4 weeks (compliance review required)
- User experience: No re-verification needed
- Maintenance: You maintain your KYC process
- Cost: No duplicate KYC costs
⚠️ Requires pre-approval from Coinflow compliance
Seamless Sumsub integration
- Best for: Existing Sumsub customers only
- Setup time: 1-2 weeks (tri-party agreement)
- User experience: Automatic data sharing, no re-verification
- Maintenance: Sumsub handles verification
- Cost: Uses existing Sumsub subscription
📋 Requires tri-party data sharing agreement
Not sure which method to use?
Start with Coinflow Prebuilt KYC for the fastest integration. You can always migrate to KYC attestation or Sumsub token sharing later if you already have an existing KYC infrastructure. All methods meet the same regulatory requirements.
Verification Methods
Coinflow’s Built-In Verification
Coinflow provides a comprehensive KYC solution that handles verification for both US and non-US users.
Verifying US Users
For US-based users, call the Register User endpoint with KycUsRequestBody. This initiates an instant database verification using:
- Email address
- Full name
- Physical address
- Country
- Date of birth
- Last 4 digits of SSN
Verification Flow:
- Instant Verification Success: If the instant database check succeeds, the user is immediately verified
- Additional Verification Needed: If instant verification fails, the API returns a 451 response with:
- A
verificationLinkfor the user to complete verification - User status set to
pending - User must take a selfie and enter their full SSN
- Upon completion, user is redirected to your specified
redirectLink
- A
Verifying Non-US Users
For international users, use the Register User endpoint with KycDocVRequestBody.
Verification Flow:
- Request typically includes only email and country
- Always returns a 451 response requiring additional verification
- User is directed to
verificationLinkto:- Upload a photo ID (passport, driver’s license, etc.)
- Take a selfie for identity confirmation
- After successful verification, user is redirected to your
redirectLink
Note: Merchants using Coinflow’s prebuilt UI components (like
CoinflowWithdraw) don’t need to handle verification flows manually - it’s built into the UI.
KYC Attestation (KYC Reliance)
If you’re using your own KYC provider (other than Sumsub), you can share verified user data with Coinflow through KYC attestation. This method requires pre-approval from Coinflow’s compliance team to ensure your KYC process meets regulatory standards.
Setup Process:
-
Request the Questionnaire
- Contact Coinflow to receive the KYC Reliance Questionnaire
-
Submit for Review
- Complete and submit the questionnaire
- Wait for final compliance approval before proceeding to production
-
Enable KYC Attestation in Sandbox
- Request Coinflow to enable KYC attestation for your sandbox environment
- Provide your sandbox merchant ID
-
Integrate the API
- Use the KYC Attested Endpoint after approval
- Deploy to production only after compliance approval
Fallback Option: If your KYC reliance application is not approved, you can use the Passing External KYC Data method instead.
Passing External KYC Data to Coinflow
If you have your own KYC provider (other than Sumsub) and aren’t approved for KYC attestation, you can pass verified user data to Coinflow using the Register User via Document endpoint.
How It Works:
-
Submit user data to Coinflow including:
- Email address
- Country
- Front and back photos of government-issued ID
-
Coinflow attempts to verify the submitted data
-
Two Possible Outcomes:
- Verification Success: User is immediately verified
- Verification Needed: API returns 451 response with a
verificationLinkfor additional verification
When Additional Verification is Required:
If Coinflow cannot verify the submitted data, the user must complete additional steps:
- Click the
verificationLinkto access the verification portal - Upload a photo ID
- Take a selfie for identity confirmation
- Upon completion, redirect to your specified
redirectLink
Why Might a 451 Response Occur?
KYC providers vary in their data collection methods and verification standards. Even if your provider has verified a user, Coinflow may require additional verification to meet our compliance requirements.
Important for UI Integration: If you’re using Coinflow’s prebuilt UI components (e.g.,
CoinflowWithdraw), call this endpoint before rendering the component to ensure the verification record exists.
Sumsub Token Sharing
If you already use Sumsub for KYC verification, you can share that data directly with Coinflow, eliminating the need for users to verify again.
Requirements:
- Active Sumsub account with verified users
- Tri-party data sharing agreement signed through Sumsub
- This agreement allows Coinflow to reuse existing KYC data you’ve collected
Setup Process:
-
Contact Coinflow
- Provide your Sumsub client ID
- Request Coinflow’s Sumsub client ID for the tri-party agreement
-
Sign Tri-Party Agreement
- Work with Sumsub to establish the data sharing agreement
- Learn more about Sumsub’s reusable KYC
-
Integrate the APIs
- Call Sumsub’s Generate Share Token endpoint to obtain a token
- Call Coinflow’s Register User Via Share Token endpoint to pass KYC data
Important for UI Integration: If you’re using Coinflow’s prebuilt UI components (e.g.,
CoinflowWithdraw), call the Register User Via Share Token endpoint before rendering the component.

