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Visa Acceptance Solutions

Checkout Experience

Build a fast, secure checkout with a single client-side library, add card-on-file recognition with Click to Pay, and collect payments without a full integration through Pay by Link.

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Why Build a Unified Checkout Experience

Customers abandon checkout when it is slow, unfamiliar, or asks for information the merchant does not need. Each guide below solves a specific part of that friction: Unified Checkout consolidates card, digital wallet, and alternative payment options behind one client-side library; Click to Pay recognizes a returning customer's card-on-file across merchants; and Pay by Link lets a merchant collect payment without building a checkout page.

This guide covers five areas of the checkout experience: Unified Checkout for accepting card, digital wallet, and alternative payments; Click to Pay for card-on-file recognition; Pay by Link for collecting payment without a full checkout integration; and Microform and Flex API v2 for tokenizing sensitive payment data before it reaches your server.

  • Unified Checkout — A single server-side component and client-side JavaScript library for accepting card, digital wallet, and alternative payments on your e-commerce page.
  • Click to Pay — Integrate Click to Pay with the Unified Checkout Drop-In UI so returning customers can check out with a recognized card on file.
  • Pay by Link — Create and manage payment links and donation links for collecting payments without a full checkout integration.
  • Microform — Replace sensitive card and check input fields with secure, brand-hosted fields that tokenize payment data on the customer's device before it reaches your server.
  • Flex API v2 — Secure payment information captured from server-side or non-browser client code by exchanging it for a transient token before it reaches your systems.

Unified Checkout and Click to Pay Drop-In UI

Unified Checkout and the Click to Pay Drop-In UI solve different parts of the checkout experience. Use this comparison to decide which one fits your integration:

Unified Checkout

Best for
Accepting card, digital wallet, and alternative payment methods in a single checkout embed
Message construction
Your server calls the Sessions API and receives a signed capture context JWT
Encryption (MLE)
The capture context includes a transaction-specific public key to secure the transaction in the browser
Security credentials
Merchant ID and API key authenticate the server-to-server Sessions API call
Setup steps
5 steps
Ideal for
Merchants building a full checkout experience with multiple payment methods
  1. Enable Unified Checkout
  2. Set up the server-side component
  3. Set up the client-side component
  4. Configure Unified Checkout
  5. Test your integration

 

Click to Pay Drop-In UI

Best for
Recognizing a returning customer's card-on-file without a full checkout rebuild
Message construction
Your server calls the Sessions API and receives a signed capture context JWT
Encryption (MLE)
The capture context includes a transaction-specific public key to secure the transaction in the browser
Security credentials
Merchant ID and API key authenticate the server-to-server Sessions API call
Setup steps
5 steps
Ideal for
Merchants who already have a checkout and want to add card-on-file recognition
  1. Add Click to Pay to a merchant account
  2. Enable Click to Pay
  3. Request the capture context (server-side)
  4. Set up the client-side SDK
  5. Configure your integration

 

Microform Integration and Flex API v2

Microform Integration and Flex API v2 both replace sensitive card and eCheck data with a transient token, but they secure that data at different points in your integration. Use this comparison to decide which one fits your integration:

Microform Integration

Best for
Securing card and eCheck data captured directly in the customer's browser
Message construction
Your server requests a capture context containing limited-use public keys from the Flex API v2 suite
Encryption (MLE)
Payment data is encrypted on the customer's device before HTTPS transmission
Security credentials
Merchant ID and API key authenticate the server-side capture context request
Setup steps
3 steps
Ideal for
Merchants who collect card or eCheck data from a client-side payment form
  1. Create the server-side capture context
  2. Set up the client-side integration
  3. Receive and use the transient token

 

Flex API v2

Best for
Securing payment information captured from server-side or non-browser client code
Message construction
Your server generates and validates the capture context, then compiles and tokenizes the payment information directly
Encryption (MLE)
Payment data is secured with one-time public encryption keys at the point of capture
Security credentials
Merchant ID and API key authenticate the capture context and tokenization requests
Setup steps
6 steps
Ideal for
Merchants integrating from server-side or non-browser client applications
  1. Generate the capture context
  2. Validate the capture context
  3. Compile the payment information in JWE format
  4. Tokenize the payment information
  5. Validate the transient token
  6. Use the transient token to process a payment

 

Pay by Link lets a merchant collect payment without building a checkout page. Send a customer a hosted payment link and they pay through a page that hosts, without any client-side integration on the merchant's site.

Pay by Link supports these link types:

  • Fixed-price links — the link specifies the amount the customer pays.
  • Customer-set price links — the customer enters the amount, commonly used for donations.

A merchant can create and send links directly from the Business Center, with no code required, or generate and manage links programmatically through the Pay by Link API. Webhook notifications report when a customer pays a link.

Last published: September 29, 2026