How quickly a bank responds in that window depends greatly on the bank. In practice at decent scale, we see banks using every possible hour of that two day window to fail transactions.
An ACH debit made on Friday night technically has until open of business Wednesday to fail.
I had no idea it was the opposite in the UK.
Edit: with the exception of writing physical checks, of course. I use those when the receiver doesn’t accept Venmo or Apple Pay.
The GP was saying they use wire transfers between friends day-to-day which isn’t the case in the US.
My bank's mobile app supports cashing them in via camera. Niche use case, but nice to have it for this attempt at government agency nickle-and-diming the populace.
For payments to friends we use bank apps. Usually the receiver generates a QR code for the payment on their phone, which you scan from your bank app, sign with a pincode, and the payment is executed immediately. If you are not near you can also use their account number to transfer money instantly.
However, I have cashed some cheques - a tax refund cheque and a refund for my remaining balance when I closed a utilities account.
They have the advantage, for the sender, that you can discharge your responsibility to offer a refund by sending a letter, rather than having to interact with the other party. Of course these days you could email them a link to a web form.
No, there's already Zelle, which is fairly popular now, though not as ubiquitous as instant bank transfers in other countries: https://en.wikipedia.org/wiki/Zelle_(payment_service)
The larger banks have their own systems that only work within the bank; some smaller banks offer systems that work with any bank that offers the same system.
ACH exists, and I've used it to move money between accounts I own, but there is some friction to set up. I don't know anyone who uses it for C2C payments.
That seems rather excessive. Why on earth are Polish bank accounts so long?