I have tried enabling receiving billing addresses with PayPal sandbox by adding the following option:
REQBILLINGADDRESS=1 (documented here: https://www.paypalobjects.com/webstatic/en_US/developer/docs/pdf/pfp_expresscheckout_pp.pdf)
For the call to SetExpressCheckout.
However, I receive the following error:
'ACK': 'Failure',
'BUILD': '6675672',
'CORRELATIONID': '4d9afd327754a',
'L_ERRORCODE0': '11601',
'L_LONGMESSAGE0': 'Billing address request is not enabled for merchant',
'L_SEVERITYCODE0': 'Error',
'L_SHORTMESSAGE0': 'Request for billing address failed',
'TIMESTAMP': '2013-06-28T16:32:22Z',
'VERSION': '72.0'
I know receiving billing addresses is possible as the Humble Bundle do it here:
How do I change my sandbox account to enable billing address requests? and what do I need to do in order to enable this for a live account?