Update Mandate

Update Mandate API

Purpose : This API modify the terms of an existing, active mandate. It is particularly useful when a customer upgrades their subscription plan or wishes to extend the duration of their service. Merchant can use this API to update:

Mandate Amount : Change the maximum limit amount (e.g., upgrading from a ₹500 plan to a ₹1000 plan).
Mandate End Date : Extend or shorten the validity period of the mandate.

Environment details:

Staging Server: https://zaakstaging.zaakpay.com
Live Server: https://api.zaakpay.com

Request Type : Post

Endpoint : /transactU?v=12

Request Attributes

These are the Request Attributes of Update Mandate API

Fields	DataType	Mandatory	Description
merchantIdentifier	String	Y	Zaakpay’s unique alphanumeric merchant identifier.
encryptionKeyId	String	Y	Id of Merchant’s Public key as signed by Zaakpay.
merchantIpAddress	String	Y	The IP address of the merchant's server.
showMobile	String	N	`true` to show mobile optimized page, `false` for desktop.
mode	String	Y	1 digit only. `0` = Staging/Test, `1` = Production/Live.
returnUrl	String	N	The URL where Zaakpay will post the response.
orderDetail.orderId	String	Y	New Unique ID for this specific update request. (Do not pass the old mandate ID here).
orderDetail.amount	String	Y	The New Amount to be updated (in Paisa).
orderDetail.currency	String	Y	Currency Code. Default is `INR`.
orderDetail.email	String	Y	Customer's email address.
orderDetail.phone	String	Y	Customer's phone number.
orderDetail.productDescription	String	Y	Description of the update (e.g., "Plan Upgrade").
paymentInstrument.paymentMode	String	Y	Value: `upiCollectMandate`.
paymentInstrument.upiMandate.action	String	Y	The action to be performed. Value must be `update`.
paymentInstrument.upiMandate.payerVpa	String	Y	The VPA associated with the customer.
paymentInstrument.upiMandate.mandateParentOrderId	String	Y	The Original Order ID of the mandate that you want to update.
paymentInstrument.upiMandate.mandateConfig.endDate	String	Y	The New End Date for the mandate in `yyyy-MM-dd` format.
billingAddress.city	String	N	Customer's city.
checksum	String	Y	To be calculated on above parameters using HMAC SHA 256.

Sample Request & Response

For reference, below are the sample CURL request and Response of API . It takes all required attributes to hit the Update Mandate API.

cURL Request

We have created a sample request of Update Mandate API with all required attributes and their values, in the order in which they’ll be sent to the API.

The resulting checksum calculated should be posted to the Zaakpay API along with other required attributes.

curl --location 'https://api.zaakpay.com/transactU?v=12' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--header 'Cookie: JSESSIONID=CD982B57935E84BA7D70996C618C0C69.11.52; JSESSIONID=AE2704BE6746B7DC1B99CB4C7F9E9A06.11.36; JSESSIONID=AE2704BE6746B7DC1B99CB4C7F9E9A06.11.36; JSESSIONID=69CCAE16E0983DC36355B6307ACD196C.11.59; JSESSIONID=7F97A0CA984EF3772692ECB30C469286.165.243' \
--data-urlencode 'data={"merchantIdentifier":"f917XXXXXXXX041d164f0","encryptionKeyId":"PvoXXXXXXD9ewv","merchantIpAddress":"127.0.0.1","showMobile":"true","mode":"0","returnUrl":"https://webhook.site/f91585dd-1cXXXXXX6-9b62d6790038","orderDetail":{"orderId":"ZaaXXXXXX2224","amount":"100","currency":"INR","purpose":"1","email":"[email protected]","txnDate":"2026-03-03","phone":"9999999999","extra1":"udf1","extra2":"udf2","productDescription":"Upi P2m Collect","product1Description":"pd1","firstName":"Test_First","lastName":"Test_Last"},"paymentInstrument":{"paymentMode":"upiCollectMandate","upiMandate":{"action":"update","payerVpa":"dvbsb7K8C++I51tZ6C4cKw5YIXXXXXXdIDpPNPWBm589fHi9kXXXXXXhAtUzFdvXll0aNXXXXXoqLgjewTW0EGOe8bngbP/RIRhQoc3pXwr4fU4N3WAma9hBG/CzLwQZjan609CZcXXXXXwCrrsFfBy+B1hgxOwxFrKWwKj9oaax/EWwaJ9k0y7QTPjt4I7fH0YjrAT5QCsU6mDV65aZPoODeB0XXXXX4owehzkKphxFeXXXXXwwsUioz+U2WyYMOdadEXXXX7hTsO8kTU2Aai8sVHHmdS9Bg==","mandateParentOrderId":"ZP_XXXXXXX3967","mandateConfig":{"endDate":"2026-04-21"}}},"billingAddress":{"city":"Gurgaon"},"shippingAddress":{"city":"Gurgaon"}}' \
--data-urlencode 'checksum=bc2adXXXXXa7e4964fccba6XXXX2d83b76a645XX2d3f14e'

Sample Request

{
    "merchantIdentifier": "f917XXXXXXXXXXXXXXX164f0",
    "encryptionKeyId": "Pvo1HKJGeZD9ewv",
    "merchantIpAddress": "127.0.0.1",
    "showMobile": "true",
    "mode": "0",
    "returnUrl": "https://wXXXXXsite/f91585ddXXXXXX-85b6-9b62d6790038",
    "orderDetail": {
        "orderId": "ZaaXXXXXX224",
        "amount": "100",
        "currency": "INR",
        "purpose": "1",
        "email": "[email protected]",
        "txnDate": "2026-03-03",
        "phone": "9999999999",
        "extra1": "udf1",
        "extra2": "udf2",
        "productDescription": "Upi P2m Collect",
        "product1Description": "pd1",
        "firstName": "Test_First",
        "lastName": "Test_Last"
    },
    "paymentInstrument": {
        "paymentMode": "upiCollectMandate",
        "upiMandate": {
            "action": "update",
            "payerVpa": "dvbsb7K8C++I51tZ6C4cKw5YIhIHpgXZ794XXXXXXXXpPNPWBm589fHi9kXXXXXXXsrjlrhAtUzFdvXll0aNh9AV6RmxUc6+4oqLgjewTW0EGOe8bngbP/RIRhQoc3pXwr4fU4N3WAXXXXXXLwQZjan609CZcpqEtvNjmtcwCrrXXXXXXgxOwxFrKWwKj9oaax/EWwaJ9k0y7QTPjt4I7fH0YjrAT5QCsU6mDV65aZPoODeB0lYCeLLbXXXXXXXphxFexYkLUQphheHNjwwsUioz+U2WyYMOdadEgbq5Wy7hTsO8kTU2Aai8sVHHmdS9Bg==",
            "mandateParentOrderId": "ZP_AcXXXXXX123967",
            "mandateConfig": {
                "endDate": "2026-04-21"
            }
        }
    },
    "billingAddress": {
        "city": "Gurgaon"
    },
    "shippingAddress": {
        "city": "Gurgaon"
    }
}

Sample Response

{
    "orderDetail": {
        "orderId": "ZaakXXXXX2224",
        "amount": "100",
        "currency": "INR",
        "productDescription": "UPI Mandate",
        "email": "teXXXXXXkpay.com",
        "phone": "99XXXXX999",
        "firstName": "L5dgXXXXXNEy1rYmCg==",
        "lastName": "v+SGInyXXXXXXOZUXqio1w==",
        "txnDate": "2026-03-03",
        "purpose": "1",
        "product1Description": "pd1",
        "extra1": "udf1",
        "extra2": "udf2",
        "amountBreakdown": {}
    },
    "responseCode": "1105",
    "responseDescription": "UPI Mandate update authorized successfully",
    "doRedirect": "true",
    "paymentInstrument": {
        "paymentMode": "UPI_XXXNDATE",
        "sendOtp": false,
        "upiMandate": {
            "action": "update",
            "payerVpa": "dvbsb7K8C++I51tZ6C4cKw5YIhIHpgXZ794CEXXXXXXXX89fHi9k0xJKJS3IyHIgsrjlrhAtUzFdXXXXXXUc6+4oqLgjewTW0EGOe8bngbP/RIRhQoc3pXwr4fU4N3WAma9hBG/CzLwQZjan609CZcpqEtvNjXXXXXXy+B1hgxOwxFrKWwKj9oaax/EWwaJ9k0y7QTPjt4I7fH0YjrAT5QCsU6mDV6XXXXXvj194owehzkKphxFexYkLUQphhXXXXioz+U2WyYMOdadEgbq5Wy7hTsO8kTU2Aai8sVHHmdS9Bg==",
            "mandateParentOrderId": "ZP_AcXXXXXr_123967",
            "mandateConfig": {
                "endDate": "Apr 21, 2026, 12:00:00 AM"
            }
        }
    },
    "bankPostData": {
        "txnid": ""
    },
    "paymentMode": "UPI_MANDATE"
}

Checksum Calculation

Create a string(JSON) using the request attributes as given below. Checksum string will create based on the request attributes which are posted to Zaakpay as same as given in the string below.

Now, Calculate the checksum using the HMAC SHA-256 algorithm using the string as data and your generated secret key. The resulting checksum calculated should be posted to the Zaakpay API along with other data.

The Checksum string will be:

Secret Key used: 0678056d96914a8583fb518caf42828a

{"orderDetail":{"orderId":"ZaakXXXXX2224","amount":"100","currency":"INR","productDescription":"UPI Mandate","email":"teXXXXXXkpay.com","phone":"99XXXXX999","firstName":"L5dgXXXXXNEy1rYmCg==","lastName":"v+SGInyXXXXXXOZUXqio1w==","txnDate":"2026-03-03","purpose":"1","product1Description":"pd1","extra1":"udf1","extra2":"udf2","amountBreakdown":{}},"responseCode":"1105","responseDescription":"UPI Mandate update authorized successfully","doRedirect":"true","paymentInstrument":{"paymentMode":"UPI_XXXNDATE","sendOtp":false,"upiMandate":{"action":"update","payerVpa":"dvbsb7K8C++I51tZ6C4cKw5YIhIHpgXZ794CEXXXXXXXX89fHi9k0xJKJS3IyHIgsrjlrhAtUzFdXXXXXXUc6+4oqLgjewTW0EGOe8bngbP/RIRhQoc3pXwr4fU4N3WAma9hBG/CzLwQZjan609CZcpqEtvNjXXXXXXy+B1hgxOwxFrKWwKj9oaax/EWwaJ9k0y7QTPjt4I7fH0YjrAT5QCsU6mDV6XXXXXvj194owehzkKphxFexYkLUQphhXXXXioz+U2WyYMOdadEgbq5Wy7hTsO8kTU2Aai8sVHHmdS9Bg==","mandateParentOrderId":"ZP_AcXXXXXr_123967","mandateConfig":{"endDate":"Apr 21, 2026, 12:00:00 AM"}}},"bankPostData":{"txnid":""},"paymentMode":"UPI_MANDATE"}

bc2ad834XXXXXe4964fccba6XXXXX951402d8XXXXX7be5e2d3f14e