# Auxiliary procedures {#en_gate_procedures}

Articles about auxiliary procedures that can be required during processing specific payments via Gate.

This section provides the information about the procedures that can be required for processing certain payments.

-   [3‑D Secure authentication](en_gate_payment_3ds.md)—about customer authentication with the use of protocol 3‑D Secure 2 for ensuring secure payment processing.
-   [3‑D Secure authentication on merchant side](en_gate_merchant_3ds.md)—about an additional variant of customer authentication with the use of the 3‑D Secure protocol on the merchant web service side.
-   [Authentication on merchant's request](en_gate_payment_merch_auth.md)—about the procedure of additional customer authentication that can be used as an alternative to the 3‑D Secure authentication and is performed upon the merchant's request.
-   [Using the Address Verification Service](en_Gate_avs.md)—about the procedure of verifying the customers' postal codes and addresses to ensure secure processing of payments with the use of the American Express, Mastercard, and Visa cards.
-   [Using the Verification of Payee service](en_verification_of_payee.md)—about the procedure of verifying the customers' names when they issue a request to receive the funds, in order to ensure that bank transfers using the SEPA payment scheme comply with the European Union Instant Payments Regulation.
-   [Submission of additional payment information](en_Gate_Clarification.md)—about the procedure of providing additional data that can be requested by payment systems in separate cases.
-   [Currency conversion](en_Gate_Conversion.md)—about processing payments in different currencies for the customer and the merchant with the conversion involved.

-   **[3‑D Secure authentication](en_gate_payment_3ds.md)**  
An article about primary workflows of authenticating customers with the use of the 3‑D Secure protocol for processing card payments via Gate, performed through the Ecommpay platform.
-   **[3‑D Secure authentication on merchant side](en_gate_merchant_3ds.md)**  
An article about an additional option of authenticating customers with the use of the 3‑D Secure protocol for processing card payments via Gate, performed through third-party solutions and initiated by the merchant.
-   **[Authentication on merchant's request](en_gate_payment_merch_auth.md)**  
An article about the procedure of authenticating customers upon merchant's request that can be used as an alternative to the 3‑D Secure authentication for processing card payments via Gate.
-   **[Using the Address Verification Service](en_Gate_avs.md)**  
An article about the procedure of verifying customers' postal codes and addresses for processing American Express, Mastercard, and Visa payments via Gate.
-   **[Using the Verification of Payee service](en_verification_of_payee.md)**  
An article about the procedure of verifying customers' names when payouts to bank accounts using the SEPA payment scheme are initiated via Gate.
-   **[Submission of additional payment information](en_Gate_Clarification.md)**  
An article about the procedure of specifying additional data that can be requested by payment systems during payment processing via Gate.
-   **[Currency conversion](en_Gate_Conversion.md)**  
An article about processing payments via Gate in different currencies with currency conversion.

**Parent topic:**[Gate](en_Gate_Integration_About.md)