Maybe the answer is more interesting in Europe, where electronic payment systems existed long before smartphones and the WWW. You would probably pay by giro,

Maybe the answer is more interesting in Europe, where electronic payment systems existed long before smartphones and the WWW. You would probably pay by giro, very commonly used to pay utility bills etc. The tax office provides a pre-printed machine-readable giro slip, which looks similar to a cheque but includes your tax number and amount owed (or electric company account number etc). You take that to your own bank, and they transfer the money from your account to the tax office's account -- originally this might be partly by post, but at least the printed slip is much more machine-readable than a cheque. I think by the 1980s the slips were no longer posted around, the payment was electronic. Of course, you could take cash to pay in to your account at the same time. You could also take the giro to a post office, and pay in cash. Or you could write a cheque and post both the cheque and the giro to the giro processing centre. I think postage was free. The in-person parts of the system still exists, though I think the post-a-cheque bit has gone. It remains the default way to pay a bill (including a tax bill) with cash or without using a computer. Before that, I don't know, since before the giro system most people in the UK didn't have bank accounts. https://en.wikipedia.org/wiki/Giro_(banking) https://en.wikipedia.org/wiki/Giro_(banking) Picture of a current giro slip, at the bottom of the bill: https://bionic.co.uk/business-energy/guides/business-energy-bills/ https://bionic.co.uk/business-energy/guides/business-energy-... The MP proposing the system in Parliament in 1965, noting it already existed in most western European countries: https://api.parliament.uk/historic-hansard/commons/1965/jul/21/postal-giro-service https://api.parliament.uk/historic-hansard/commons/1965/jul/... -- "this is a simple system of credit transfer which can be operated through our network of 23,000 post offices throughout the country ... All these giro clearing houses are linked together by Telex machine".