PayPal user identifier - paypal

Question

I'm trying to find some hard identifier that don't change during PayPal account lifetime,
It seems like the REST API has its own user identifier (that can be returned from the openidconnect/userinfo resource when scope has openid)
Unfortunately, This ID is not what the Adaptive API expect when issuing a PayRequest:
sender.accountId: Account ID value (which is the same as the Payer ID value used in the Express Checkout API). The account ID value is an encrypted PayPal account ID.
This is confusing, I understand the REST API is different than the Adaptive API and using email is not sufficient because we need to store the identifier on our database for long term and user may change his email address through PayPal,
Thanks,
Asaf.

Answer 1

You don't need the sender ID when working with preapproved payments. The preapproval key itself relates to the sender who approved it.
Here's a sample request and response for Pay using a preapproval key that works just fine without any sender ID.
Request
<?xml version="1.0" encoding="utf-8"?>
<PayRequest xmlns="http://svcs.paypal.com/types/ap">
<requestEnvelope xmlns="">
<detailLevel>ReturnAll</detailLevel>
<errorLanguage>en_US</errorLanguage>
</requestEnvelope>
<actionType xmlns="">PAY</actionType>
<cancelUrl xmlns="">http://paypal.angelleye.com/paypal/class/1.2/Pay_Cancel.php</cancelUrl>
<clientDetails xmlns="">
<applicationId xmlns="">APP-80W284485P519543T</applicationId>
<ipAddress xmlns="">192.168.1.1</ipAddress>
</clientDetails>
<currencyCode xmlns="">USD</currencyCode>
<preapprovalKey xmlns="">PA-2AY45015CC5060422</preapprovalKey>
<receiverList xmlns="">
<receiver xmlns="">
<amount xmlns="">5.00</amount>
<email xmlns="">usb_1329725429_biz#angelleye.com</email>
</receiver>
</receiverList>
<sender>
<useCredentials xmlns=""></useCredentials>
</sender>
<account xmlns="">
<phone xmlns=""></phone>
</account>
<returnUrl xmlns="">http://paypal.angelleye.com/paypal/class/1.2/Pay_Return.php</returnUrl>
</PayRequest>
Response
<?xml version='1.0' encoding='UTF-8'?>
<ns2:PayResponse xmlns:ns2="http://svcs.paypal.com/types/ap">
<responseEnvelope>
<timestamp>2013-09-24T13:57:52.350-07:00</timestamp>
<ack>Success</ack>
<correlationId>2fa4316b879b9</correlationId>
<build>7767516</build>
</responseEnvelope>
<payKey>AP-5632737798659023M</payKey>
<paymentExecStatus>COMPLETED</paymentExecStatus>
<paymentInfoList>
<paymentInfo>
<transactionId>53664474R26308454</transactionId>
<transactionStatus>COMPLETED</transactionStatus>
<receiver>
<amount>5.00</amount>
<email>usb_1329725429_biz#angelleye.com</email>
<primary>false</primary>
<accountId>C9TAVNJFATXCS</accountId>
</receiver>
<pendingRefund>false</pendingRefund>
<senderTransactionId>3CV49919EJ546411E</senderTransactionId>
<senderTransactionStatus>COMPLETED</senderTransactionStatus>
</paymentInfo>
</paymentInfoList>
<sender>
<accountId>E7BTGVXBFSUAU</accountId>
</sender>
</ns2:PayResponse>
You can see above the response actually includes the sender ID which it knows based on the preapproval key provided in the request.