Root Cause

• Strong Customer Authentication (SCA) required: Regulatory requirements like PSD2 mandate additional authentication for certain transactions.
• 3D Secure or equivalent authentication pending: The transaction requires the customer to complete a verification step through their bank or payment provider.
• High-risk transaction flagged: The payment gateway or issuer flagged the transaction for additional security verification due to its risk profile.
• Incomplete identity verification: The customer has not yet completed all required identity verification steps.

Troubleshooting and Solutions

• Ask the customer to follow the on-screen instructions or authentication prompts to complete the verification process.
• For pending invoices, you can send ‘Pay Now’ link via Email and guide the customer to use the 'Pay Now' link to complete 3DS and pay pending invoices.
• If authentication fails, advise the customer to try again or contact their bank for assistance.
• Recommend using a different payment method that doesn’t require additional authentication, if available.
• Ensure that your payment integration supports required authentication flows like 3D Secure.
• Clearly inform customers in advance if additional authentication will be required for smoother transaction completion.