Here in Brazil, ISP and other bills usually come in the form of a Boleto Bancário (https://en.wikipedia.org/wiki/Boleto_Banc%C3%A1rio), which you can pay with cash at the bank (or at lottery stores). Utility bills use a similar system. From the point of view of the bill issuer, it's cashless.

I don't know how it works on other countries, but I'd expect similar systems.