Recognise members at checkout

Read the card with a CardAcquisition request before the payment. If the card belongs to a member, the response has the member number. The Payment then reuses the card, so the customer taps only once.

Requirements

Requirement	Description
Set-up	ID lookup is turned on for your terminals. See Set up ID lookup
Before you start	Your ECR is connected and logged in. See Connect your ECR
Messages	CardAcquisition · Payment · EnableService

The flow

sequenceDiagram
    participant P as Your POS
    participant T as Terminal
    participant L as Your loyalty program
    P->>T: CardAcquisition request (with amount)
    Note over T: Customer taps card, terminal looks it up
    T-->>P: CardAcquisition response
    alt Member found
        P->>L: Get benefits for the member number
        L-->>P: Discount or points
        P->>T: Payment with CardAcquisitionReference
    else No member
        P->>P: Offer sign-up or continue without
        P->>T: Payment, or EnableService (AbortTransaction)
    end

1. Read the card

Send CardAcquisition. Include TotalAmount and PaymentType = Normal when a payment follows. To only identify the customer, leave out the amount and PaymentType.

Example CardAcquisition request

{
  "SaleToPOIRequest": {
    "MessageHeader": {
      "ProtocolVersion": "3.1",
      "MessageClass": "Service",
      "MessageCategory": "CardAcquisition",
      "MessageType": "Request",
      "ServiceID": "2",
      "SaleID": "ECR123",
      "POIID": "AT12345"
    },
    "CardAcquisitionRequest": {
      "SaleData": {
        "SaleTransactionID": {
          "TransactionID": "12345678",
          "TimeStamp": "2026-10-13T13:30:00+02:00"
        }
      },
      "CardAcquisitionTransaction": {
        "TotalAmount": 125.00,
        "PaymentType": "Normal"
      }
    }
  }
}

2. Read the result

Check that Result is Success, then look for LoyaltyAccount:

What you get	What it means	What the POS does
`LoyaltyAccount` with your program	The card belongs to a member	Read `LoyaltyBrand` and `LoyaltyID`, get the benefits
`LoyaltyAccount` with a partner's program	The customer is a member of a partner's program (cross loyalty)	Apply the partner benefit, if you have one
Temporary identity	The customer signed up on the terminal but hasn't finished in your loyalty program	Remind the customer to finish signing up
No `LoyaltyAccount`	The card isn't linked to a member. The customer may still be a member with another card	Offer sign-up, link the card, or continue without. See Enrol members at the terminal

Example CardAcquisition response with a member

{
  "SaleToPOIResponse": {
    "MessageHeader": {
      "ProtocolVersion": "3.1",
      "MessageClass": "Service",
      "MessageCategory": "CardAcquisition",
      "MessageType": "Response",
      "ServiceID": "2",
      "SaleID": "ECR123",
      "POIID": "AT12345"
    },
    "CardAcquisitionResponse": {
      "Response": {
        "Result": "Success",
        "AeResponseCode": "000"
      },
      "POIData": {
        "POITransactionID": {
          "TransactionID": "87654321",
          "TimeStamp": "2026-10-13T13:30:03+02:00"
        }
      },
      "PaymentInstrumentData": {
        "PaymentInstrumentType": "Card",
        "CardData": {
          "PaymentBrand": "MASTERCARD",
          "MaskedPAN": "540481******1761"
        }
      },
      "LoyaltyAccount": [
        {
          "LoyaltyBrand": "PARTNER_REWARDS",
          "LoyaltyAccountID": {
            "LoyaltyID": "MEMBER123456"
          }
        }
      ]
    }
  }
}

3. Pay with a single tap

Get the benefits from your loyalty program and work out the final amount.
Send Payment. Copy POITransactionID from the CardAcquisition response into CardAcquisitionReference.
The amount must not be higher than in the CardAcquisition request, and PaymentType must be the same.

🚧
Don't pay after an abort
If the card acquisition was aborted before the card was read (STOP pressed, timeout or Abort from the ECR), the response has ErrorCondition = Aborted. Don't send the payment automatically: the cashier or customer wanted to stop.

4. Always finish or abort

If no Payment or BalanceInquiry follows, send EnableService with TransactionAction = AbortTransaction. Otherwise the terminal keeps the card session open.

Offer sign-up when no member is found: Enrol members at the terminal.

Requirements

The flow

1. Read the card

2. Read the result

3. Pay with a single tap

Don't pay after an abort

4. Always finish or abort

Next