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Unzer

Accept Unzer Bank Transfer with a server-side-only integration

Build your own payment form to add Unzer Bank Transfer payment to the checkout page

Overview

The customer can use Unzer Bank Transfer to conveniently pay using their own banking network. After selecting Unzer Bank Transfer as a payment method, they are redirected to our PIS (Payment Initiation Service) endpoint where they can authorize the payment.

Before you begin

Step 1: Create a payment type resource
server side

When creating the payment type Unzer Bank Transfer, you need to send a request to the Unzer API. The response contains an id , this is later referred to as typeId. You will need this typeId to perform the transaction.

POST https://api.unzer.com/v1/types/pis

Body: {}      
$unzer = new UnzerSDK\Unzer('s-priv-xxxxxxxxxx');

$pis = new UnzerSDK\Resources\PaymentTypes\PIS();
$pis = $unzer->createPaymentType($pis);
Pis pis = new Pis();
Unzer unzer = new Unzer(new HttpClientBasedRestCommunication(), "s-priv-xxxxxxxxxx");
pis = unzer.createPaymentType(pis);

The response looks similar to the following example:

{
    "id": "s-pis-ynkylhm788ro",
    "method": "PIS",
    "recurring": false,
    "geoLocation": {
        "clientIp": "127.0.0.1",
        "countryCode": "DE"
    }
}

For more details on Unzer Bank Transfer payment type creation, see API reference.

Step 2: Make a payment
server side

Make a charge transaction

Now, make a charge transaction with the FlexiPayDirect typeId that you created and the returnUrl leading back to your shop after the payment is finished on the external page. With the charge transaction, an amount is requested but is not yet transferred. Initially, the transaction is pending and a payment resource is created.

POST https://api.unzer.com/v1/payments/charges
   
{
  "amount" : "20",
  "currency": "EUR",
  "returnUrl": "https://www.my-shop-url.de/returnhandler",
  "resources" : {
    "typeId" : "s-pis-jldsmlmiprwe"
  }
}
$unzer = new Unzer('s-priv-xxxxxxxxxx');
$unzerBankTransfer = $unzer->fetchPaymentType('s-pis-0ajzmaxcuvhc');
$charge = $unzerBankTransfer->charge(20.0, 'EUR', 'https://www.my-shop-url.de/returnhandler');
Unzer unzer = new Unzer("s-priv-xxxxxxxxxx");
Charge charge = unzer.charge(BigDecimal.ONE, Currency.getInstance("EUR"), "s-pis-0ajzmaxcuvhc", new URL("https://www.my-shop-url.de/returnhandler"));

The response looks similar to the following example:

{
    "id": "s-chg-1",
    "isSuccess": false,
    "isPending": true,
    "isError": false,
    "redirectUrl": "https://payment.unzer.com/v1/redirect/pis/s-sGYdGywWpxzW",
    "message": {
        "code": "COR.000.100.112",
        "merchant": "Request successfully processed in 'Merchant in Connector Test Mode'",
        "customer": "Your payments have been successfully processed in sandbox mode."
    },
    "amount": "20.0000",
    "currency": "EUR",
    "returnUrl": "https://www.my-shop-url.de/returnhandler",
    "date": "2021-05-10 00:51:03",
    "resources": {
        "paymentId": "s-pay-131937",
        "traceId": "70ddf3152a798c554d9751a6d77812ae",
        "typeId": "s-pis-jldsmlmiprwe"
    },
    "paymentReference": "",
    "processing": {
        "uniqueId": "31HA07BC8157BD2BC04D483EFA914465",
        "shortId": "4845.3426.1987",
        "traceId": "70ddf3152a798c554d9751a6d77812ae"
    }
}

For a full description of the charge transaction, refer to the relevant server-side integration documentation page: Charge a payment (direct API calls), Charge a payment (PHP SDK), Charge a payment (Java SDK).

Forward the customer to external payment page

After you charge the FlexiPayDirect resource, implement the following flow:

  1. Forward the customer to the redirectURL returned in the response to your charge request.
  2. The customer is forwarded to the Unzer Bank Transfer payment page.
  3. After a successful payment or abort on the pis page, the customer is redirected to the returnURL specified in the initial Charge call.

Step 3: Check status of the payment
server side

Once the customer is redirected to the returnUrl, you can fetch the payment details from the API, by using the resources.paymentId from the charge response above to handle the payment according to its status. If the status of the payment is completed , the payment process has been finished successfully and can be considered as paid. You can check all the possible payment states here.

GET https://api.unzer.com/v1/payments/{resource_ID}>/charges/{transaction_ID}

{
    "id": "s-pay-131937",
    "state": {
        "id": 1,
        "name": "completed"
    },
    "amount": {
        "total": "20.0000",
        "charged": "20.0000",
        "canceled": "0.0000",
        "remaining": "0.0000"
    },
    "currency": "EUR",
    "orderId": "",
    "invoiceId": "",
    "resources": {
        "customerId": "",
        "paymentId": "s-pay-131937",
        "basketId": "",
        "metadataId": "",
        "payPageId": "",
        "traceId": "70ddf3152a798c554d9751a6d77812ae",
        "typeId": "s-pis-grpucjmy5zrk"
    },
    "transactions": [
        {
            "date": "2021-05-10 00:51:03",
            "type": "charge",
            "status": "success",
            "url": "https://api.unzer.com/v1/payments/s-pay-131937/charges/s-chg-1",
            "amount": "20.0000"
        }
    ]
}

Step 4: Display the payment result
client side

Use the information from the Check status of the payment step to show payment result to your customer.
This can be the success or error page of your shop. If something went wrong you can use the client message from the API response and show it to the customer.

Manage payment
server side

For more details on managing Unzer Bank Transfer payments, see Manage Unzer Bank Transfer payments

Notifications

We recommend subscribing to the payment event to receive notifications about any changes to the payment resource. As soon as the event is triggered you should fetch the payment and update the order status in your shop according to its status.

  {
    "event":"payment.pending",
    "publicKey":"s-pub-xxxxxxxxxx",
    "retrieveUrl":"https://api.unzer.com/v1/payments/s-pay-774",
    "paymentId":"s-pay-774"
  }

For more details on implementing webhooks to receive notifications, see Notifications page.

Error handling

All requests to the API can result in an error that should be handled. Refer to the Error handling guide to learn more about Unzer API (and other) errors and handling them.

Test & go live

You should always test your integration before going live. First perform test transactions using test data. Next, check against Integration checklist and Go-live checklist to make sure the integration is complete and you’re ready to go live.

See also