One thing about checks that perhaps doesn't get touched on a lot...plenty of businesses use them as part of their accounts payable process wherein they are invoiced on some type of payment terms (whether it's due on receipt or commonly within 30/60/90 days). An unintended but extremely (ab)used feature here is being able to pad out the actual time between receipt of invoice and when the money actually leaves your bank account because 'check is in the mail, should be there in a few days' is an acceptable answer when accounts receivable on the other end inquires about your overdue payment, effectively turning net 30 into net 40. Now, same could in theory be said for ACH since it takes up to a few days to settle depending on the hops between banks, but setting up each vendor's ACH details in a system that may or may not be set up to even do so is overhead compared to cutting checks. All in, the massive inefficiency leads to a vicious cycle of everyone in the chain getting paid late and then doing the same forward. Which sucks.