.svg)
.svg)
.svg)
.svg)
.svg)
The unified orchestration layer for wallets and alternative payments
.svg)
The secure repository for all your payment methods
.svg)
Workflow-driven payments intelligence for smarter routing and higher auth rates
.svg)
A flexible fraud and authentication layer. Instantly add advanced fraud tools and 3DS
One integration to sell inside ChatGPT, Gemini, and every agentic platform
The visual workflow builder that ties fraud, identity, and payment routing together in one place
The unified orchestration layer for wallets and alternative payments
The secure repository for all your payment methods
Workflow-driven payments intelligence for smarter routing and higher auth rates
A flexible fraud and authentication layer. Instantly add advanced fraud tools and 3DS
One integration to sell inside ChatGPT, Gemini, and every agentic platform
The visual workflow builder that ties fraud, identity, and payment routing together in one place
Single Message Transaction
A single message transaction is a payment processing model in which authorization and settlement are combined into a single real-time message, the transaction is both approved and submitted for settlement simultaneously, without the two-step separation characteristic of the Dual Message Transaction model. Funds are committed to movement in the same exchange that approves the payment.
Single message transactions are the standard for PIN debit transactions processed through debit networks (Interlink, NYCE, Star, Pulse, and similar US debit networks), where the cardholder's PIN provides sufficient authentication to justify immediate, irrevocable fund movement. They are also used for ACH (Automated Clearing House) transactions and some other bank-transfer-based payment methods.
The key characteristic of single message transactions, and what distinguishes them operationally from Dual Message Transactions, is that there is no separate capture step. The merchant submits one request and the payment is both authorized and committed to settlement in that single exchange. There is no window to modify the amount after the fact, and Void operations are more constrained because the transaction is immediately scheduled for settlement rather than sitting in an authorized-but-not-captured state.
From a consumer's perspective, single message PIN debit transactions clear faster from their bank account than dual message signature debit or credit transactions, the fund reservation converts to a settled transaction more quickly because the authorization-settlement separation does not exist.
Frequently Asked Questions
Can a single message transaction be reversed?
Reversals of single message transactions are handled differently than voids in the dual message model. Because the transaction is immediately submitted for settlement, a void is technically a reversal request sent to the network to cancel the settlement before it completes, a very short window. After that window closes, a Refund (credit transaction) is the only mechanism for returning funds.
Why are PIN debit transactions processed as single message while signature debit transactions use dual message?
The distinction reflects historical network infrastructure and liability frameworks. PIN debit transactions are processed through separate debit networks (not Visa/Mastercard signature rails) that were designed for immediate fund movement, PIN authentication provides the real-time verification that makes immediate settlement appropriate. Signature debit transactions run over Visa and Mastercard signature rails, the same infrastructure as credit cards, and therefore inherit the dual message model of those networks.
Is the single message model more efficient than dual message?
From a raw settlement speed perspective, single message is more direct, the authorization and settlement commitment happen in one exchange rather than two. However, dual message's separation provides operational flexibility that single message cannot. For most merchants, the choice between models is not an active decision, it is determined by the payment method and gateway configuration.
