Collect Additional Charges

The following are the different methods to implement additional charges for PayU Hosted Checkout or Merchant Hosted Checkout:

• Enable additional charges from PayU backend
• Post additional charges along with amount

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Reference:

The hash algorithm indicated in the below procedures are for _payment API for PayU Hosted Checkout and Merchant Hosted Checkout. For more information, refer to Collect Payment API - PayU Hosted Checkout or Collect Payment API - Merchant Hosted Checkout based on your integration.

Enable additional charges from PayU backend

In this method, you will be posting only the transaction amount of the product in the transaction request. PayU adds the additional amount based on your request with PayU.

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Note:

To enable the additional charges facility, you need to contact PayU Support.

1. Customer clicks the Pay Now button and the additional amount will be added to the amount of the product by PayU (based upon the TDR values).

The total amount would be passed on to the bank’s page while re-directing.

2. PayU receives the status of the transaction from the bank.
3. PayU sends the response back to the merchant. In this response, the amount and additional amount can be differentiated with the following parameters:

4. Check the authenticity of the response by reverse hashing.

Here, if the additionalCharges parameter is posted in the transaction response, then the hash formula is:

sha512(additional_charges|SALT|status||||||udf5|udf4|udf3|udf2|udf1|email|firstname |productinfo|amount|txnid|key)

If additionalCharges parameter is not posted in the transaction response, then the hash formula is the generic reverse hash formula:

sha512(SALT|status||||||udf5|udf4|udf3|udf2|udf1|email|firstname|productinfo|amo unt|txnid|key)

Post additional charges along with amount

To post additional charges along with the transaction amount:

1. Posting both the transaction amount and additional charges in the transaction request. The parameters used in this regard are:

The order of the parameters is as follows:

<bankcode1> :< additional charge value>, < bankcode2> :< additional charge value>

Example

CC:12,AMEX:19,SBIB:98,DINR:2,DC:25,NB:55

Note: In this method of applying additional charges, the hash sequence would be affected for both pre-Transaction and post-transaction.

You need to form the following hash sequence before posting the transaction to PayU:

sha512(key|txnid|amount|productinfo|firstname|email|udf1|udf2|udf3|udf4|udf5|||| ||SALT|additional_charges)

Where additional_charges parameter will be substituted with additional charges for each payment mode. For example, the additional charges for each payment mode can be found in the following code block:

CC:12,AMEX:19,SBIB:98,DINR:2,DC:25,NB:55

After the transaction request hits the PayU server and re-direction, the customer lands on the PayU payment page. Based on the payment mode selected by the customer, the additional charge value will be added to the transaction amount. In the above example, the additional amount is charged according to the payment mode:

• Rs 12 for credit card
• Rs.19 for AMEX option
• Rs 98 for SBI Net Banking
• Rs 2 for Diners card
• Rs. 25 for debit card
• Rs. 55 for Net Banking with other banks

Note: The additional charges would be added only once the customer clicks the Pay Now option.

2. PayU receives the response from the bank.

3. PayU makes a POST Response to the merchant. The hash sequence needs to be changed in this regard.

   You need to form the following hash sequence and verify it with the hash sent by PayU in the Post Response:

sha512(additionalCharges|SALT|status||||||udf5|udf4|udf3|udf2|udf1|email|firstname |productinfo|amount|txnid|key)

The additionalCharges value must be the same as the value posted from PayU to the merchant in the response.

4. Compare the hash value with the hash value posted by PayU to you.

If both match, you must process the order. If they don’t match, the transaction has been tampered with and should not be processed further.