ACH has been next day for like 2 years now at least with every bank and employer I’ve used. I’m sure there’s some banks that didn’t join the next day system, but I haven’t experienced it. Then again being part of a credit union has lost a lot of its allure these last few years, so maybe that’s where you’d see that sort of thing more.
I just received a next-day ACH via Apple savings to my credit union. CUs still have their allure, I'll never get over Wells Fargo charging me fees for minimum account balances when I was 18 and working for minimum wage. What a sour taste to leave in a young customers mouth and good way to shoo them away once they start gaining some value.
Yes, and only next day settlement. Because there’s no real time authorization, payments have two business days after settlement for the banks to report ordinary failures like insufficient funds.
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.