[gumby]

> Every bank check lists the bank account number, which serves as the only information needed for a party to issue a request to withdraw money from that account.

A check is simply a contract -- a promissory note. Like any contract you wouldn't sign it with someone you didn't trust, right?

(Obviously that statement, while true, is risable these days. But I remember a Bogart film in which he was setting a debt at a casino so asked the owner for a check -- he filled in not only the amount but his name, address and bank).

All the info on your check is just printed there as a convenience to you, or at least used to be. Until ~20 years ago physical checks were still sent back to your bank where they would check the signature, which could take a while! I think since the 72 hour rule went into place (and sending checks physically no longer allowed) the format was set by regulation

[singleshot_]

If you trusted the person from whom you accepted a check, why didn’t you simply accept a promise to be paid later?

Put elsewise, the salient feature of a check is that your trust in that bank backstops your lack of trust in the bearer of the checking account.

(Right? Or did I misunderstand your trust model perhaps?)

[gumby]

The check is a promise to be paid later. You are trusting the check writer that they are good for the money. The bank could refuse to honor the request if there isn’t enough money in the account or they don’t believe the document is legit (looks altered). In the not so old days* you’d have to wait for the check’s bank to accept it before you got your money.

And the writer is trusting you not to modify the check or otherwise fraudulently use the account info (in my parents’ time the check didn’t have account numbers on it so this was less of a risk).

The only backstop the bank offered was to verify the signature against the signature card and refuse the check if it looked suspicious. I think the same is still true today.

* I worked for Atari back when Warner owned them (1980s). Congress had required that companies offer direct deposit, but the minimum was they only had to offer it to you if you banked at the same bank as the company. So Atari’s payroll came out of a small bank in Sunnyvale with only one office. The rest of us got paper paychecks on Friday. Even if you went to the bank before 3 on Friday it wouldn’t be processed until Monday, which meant they’d send the physical checks to Synnyvale to be validated. Warner got to use the float on the money while all that was going on.

[singleshot_]

One brief and illuminating trip through UCC-4 and it appears you are correct. Thanks for the explanation.