[PeterisP]

The solution to bank the unbanked doesn't need a technological solution, it needs a motivation solution - banks can already "bank" everyone if they want to, but they don't. The EU approach to that is establishing a right to a basic bank account that banks can't refuse, often with a combination of ID laws that try to ensure that everyone has a gov't issued ID - and the outcome (at least local to me) is that even homeless drug/alcohol addicts begging on the street do generally have a bank account and payment card, and that is the mechanism they use, for example, for accessing any government benefits (such as social security) they may receive.

But that being said, while banking the unbanked is IMHO a good thing, I'm not convinced that it would be a meaningful change to reducing homelessness - if they get a job, they can get paid in various other ways, and the problem with loans is not with executing the loan payment, but with someone willing to lend them money and accept the risk of default.