Wanted: subsidies for electronic payments

Not so much subsidies needed - better to encourage transparent charging - common in the Nordics already to add cost of paper invoices to the invoice. Also just - those who use e-invoicing should not pay for more expensive behavior of others.

Same logic was used in bank branches already in the 80s when e-banking was introduced.

Nothing works like "negative carrots"

If they became as simple as writing a cheque, e-payments will automatically see a lot more adoption by the man on the street - there's no need for any government subsidies.

When many EU governments - Social Security in Germany, HM Revenue in the UK, to name a few - insist on using snail-mail for any letter that contains Personally Identificable Information (PII), I don't see why I should be slapped a penalty if I don't want to accept bills and invoices electronically.  

This concept may work in many countries work but you can not pursuade the people that function in the "grey or black" markets to jump on a e-payment platform.  I have been a part of several joint bank and government e-payment programs that did not meet the "consumer usage goals" and the root cause appeared to be the fear by many consumers and  merchants that all of their transactions would be tracked, analyzed and taxed by the government. 

"Cash is king" with many groups within developed and developing countries and the convenience and efficiencies that are inherent in e-payments will not overcome the issues of consumer privacy and/or financial reporting of transactions.