Paypal subscription with lower first payment amount, discount, with Rest api?

Question

We are using billing agreement with rest api and we are able to successfully do it on sandbox. Now we have requirement of discount on first month, so if the have an agreement of 100$ for every month and when user applies some referral coupon, he will get 10$ discount on 1st month .i.e he should be charge 90$ on 1st month and 100$ going forward in the agreement period. I couldn't see any option other than setup fee, but this can only be used for additional fee, i.e to increase the plan amount but not some thing less.

Answer 1

You must use paypal express checkout api to do this.

From paypal api documentation - https://developer.paypal.com/docs/classic/express-checkout/ht_ec-freeTrialRecurringPayments-curl-etc/

Using api method CreateRecurringPaymentsProfile you can change:

1. RIALBILLINGPERIOD: Period of time in one trial period. For example, a month.
2. TRIALBILLINGFREQUENCY: Frequency of charges, if any, in a period.
3. TRIALBILLINGFREQUENCY: Frequency of charges, if any, in a period.
4. TRIALTOTALBILLINGCYCLES: Trial period's length. That is, the number of periods in the trial.
5. TRIALAMT: Payment amount during the trial period. For example, zero.

You must set parameter $fields['INITAMT'] = $10; and other parameters for recurring payment to $100 for month:

$fields['INITAMT']  = 10;
$fields['L_PAYMENTREQUEST_0_AMT0'] = 100;
$fields['AMT'] = 100;

In this case you will charge 10$ immediately and after that each month will charge $100 for recurring payment.

Here one simple (PHP) example how to set a transaction with several products (also recurring payment):

// Parameters for SetExpressCheckout, which will be sent to PayPal

$padata['L_BILLINGAGREEMENTDESCRIPTION0']   = 'Product description';
$padata['L_BILLINGAGREEMENTDESCRIPTION0']   = $padata['L_BILLINGAGREEMENTDESCRIPTION0'] . 
' $'.$product->price.'/month';
$padata['L_PAYMENTREQUEST_0_DESC0']     = $padata['L_BILLINGAGREEMENTDESCRIPTION0'] . 
' $'.$product->price.'/month';
$padata['PAYMENTREQUEST_0_NOTIFYURL']         = 'http://site_url/paypal/ipn';
$padata['PAYMENTREQUEST_0_DESC']            = $product->name;
$padata['RETURNURL']                        = 'http://site_url/paypal/returnurl';
$padata['CANCELURL']                        = 'http://site_url/paypal/cancelurl';

$padata['PAYMENTREQUEST_0_CURRENCYCODE']    = 'USD';
$padata['PAYMENTREQUEST_0_PAYMENTACTION']   = 'SALE';
$padata['PAYMENTREQUEST_0_ITEMAMT']     = $product->price;
$padata['PAYMENTREQUEST_0_AMT']          = $product->price;
$padata['L_BILLINGTYPE0']                    = 'RecurringPayments';
$padata['L_PAYMENTREQUEST_0_NAME0']         = $product->name;
$padata['L_PAYMENTREQUEST_0_NUMBER0']      = '322';
$padata['L_PAYMENTREQUEST_0_QTY0']        = '1';
$padata['L_PAYMENTREQUEST_0_AMT0']          = $product->price;
$padata['L_PAYMENTREQUEST_0_NAME1']        = 'Second Product name';
$hosteddata['L_PAYMENTREQUEST_0_DESC1']    = 'second product description';
$hosteddata['L_PAYMENTREQUEST_0_NUMBER1']  = $secondproduct->id;
$hosteddata['L_PAYMENTREQUEST_0_QTY1']      = '1';
$hosteddata['L_PAYMENTREQUEST_0_AMT1']      = $secondproduct->price;

$paypal_data            = http_build_query($padata);
$httpParsedResponseAr   = $this->PPHttpPost('SetExpressCheckout', $paypal_data);

//Respond according to message we receive from Paypal
if("SUCCESS" == strtoupper($httpParsedResponseAr["ACK"]) || "SUCCESSWITHWARNING" == strtoupper($httpParsedResponseAr["ACK"])){

    //Redirect user to PayPal store with Token received.
    $paypalurl ='https://www.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token='.$httpParsedResponseAr["TOKEN"].'';
    header('Location: '.$paypalurl);

}else{
    echo 'Error : '.urldecode($httpParsedResponseAr["L_LONGMESSAGE0"]).'';


}

Script after get token on returnurl:

$hosteddata['L_BILLINGAGREEMENTDESCRIPTION0']   = 'Recurring Description';
$hosteddata['L_BILLINGAGREEMENTDESCRIPTION0']   = $hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'] . ' $'.$pr->price.'/month';
$hosteddata['L_PAYMENTREQUEST_0_NAME0']         = $pr->name;
$hosteddata['PROFILEREFERENCE']                 = $GetExpressCheckoutDetails['L_PAYMENTREQUEST_0_NUMBER0'];
$hosteddata['PROFILESTARTDATE']               = date('Y-m-d') . 'T' . date('H:i:s').'Z';
$hosteddata['SUBSCRIBERNAME']                    = $GetExpressCheckoutDetails['FIRSTNAME'] . ' ' . $GetExpressCheckoutDetails['LASTNAME'];
$hosteddata['TOKEN']                               = urlencode($_POST['token']);
$hosteddata['DESC']                              = $hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'];
$hosteddata['AMT']                               = $pr->price;
$hosteddata['BILLINGPERIOD']                  = 'Month';
$hosteddata['BILLINGFREQUENCY']                  = '1';
$hosteddata['TOTALBILLINGCYCLES']                = '12';
$hosteddata['REGULARTOTALBILLINGCYCLES']        = '1';
$hosteddata['VERSION']                           = '74.0';
$hosteddata['MAXFAILEDPAYMENTS']              = '1';
$hosteddata['L_PAYMENTREQUEST_0_QTY0']           = '1';
$hosteddata['L_BILLINGTYPE0']                    = 'RecurringPayments';
$hosteddata['L_PAYMENTREQUEST_0_ITEMCATEGORY0']  = 'Digital';
$hosteddata['L_PAYMENTREQUEST_0_AMT0']         = $pr->price;
$hosteddata['INITAMT']                            = $pr->price;
$hosteddata['L_PAYMENTREQUEST_0_NUMBER0']     = $pr->id;
$hosteddata['PAYMENTREQUEST_0_NOTIFYURL']        = 'http://site_url/paypal/ipn';

$padata['L_PAYMENTREQUEST_0_NAME1']      = 'Second Product name';
$hosteddata['L_PAYMENTREQUEST_0_DESC1']         = 'second product description';
$hosteddata['L_PAYMENTREQUEST_0_NUMBER1']       = $secondproduct->id;
$hosteddata['L_PAYMENTREQUEST_0_QTY1']            = '1';
$hosteddata['L_PAYMENTREQUEST_0_AMT1']           = $secondproduct->price;

$paypal_data = http_build_query($hosteddata);
$hosted_saas_response = $this->PPHttpPost('CreateRecurringPaymentsProfile', $paypal_data);

I used a separate method to post parameters to paypal

private function PPHttpPost( $methodName_, $nvpStr_ ) {

$api_username   = 'yourpaypal@email.com';
$api_password   = 'QWEQWEWQEQWEQEQWE';
$api_signature   = 'WQEQWEQWEQWEWQEQWEQWEQWEQWEQWE.cT';
$api_endpoint    = "https://api-3t.paypal.com/nvp";
$version     = '124.0';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api_endpoint);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_POST, 1);

$nvpreq = "METHOD=$methodName_&VERSION=$version&PWD=$api_password&USER=$api_username&SIGNATURE=$api_signature&$nvpStr_";

curl_setopt($ch, CURLOPT_POSTFIELDS, $nvpreq);
$httpResponse = curl_exec($ch);

if(!$httpResponse) {
    exit("$methodName_ failed: ".curl_error($ch).'('.curl_errno($ch).')');
}

// Extract the response details.
$httpResponseAr = explode("&", $httpResponse);

$httpParsedResponseAr = array();

foreach ($httpResponseAr as $i => $value) {
    $tmpAr = explode("=", $value);
    if(sizeof($tmpAr) > 1) {
      $httpParsedResponseAr[$tmpAr[0]] = $tmpAr[1];
    }

}

if((0 == sizeof($httpParsedResponseAr)) || !array_key_exists('ACK', $httpParsedResponseAr)) {
  exit("Invalid HTTP Response for POST request($nvpreq) to $api_endpoint.");

}

return $httpParsedResponseAr;

}