Is it acceptable that an authority issuing electronic identity cards have these used by third parties and charge for this? Klaus Schmeh, Chief Marketing Editor at cryptovision and author of numerous books and articles, has published an article in The Vault magazine about this topic. There are many possibilities for such refinancing. For example, an identity card issuer may include a credit card function in the card and have this service paid for by the credit card company. Or they can charge the vending machine operator for the proof of age used by, say, a cigarette vending machine. How something like this can be realized technically was discussed in several cryptovision lectures at Mindshare, the Security Document World and Secure Identification.
Article on Silicon Trust: https://silicontrust.wordpress.com/2018/06/29/alternative-financing-models-for-eid-projects/
Online edition of The Vault (cryptovision article on p. 26): https://silicontrust.files.wordpress.com/2018/06/the_vault_22_web.pdf