Technically, a check can be scribbled on a napkin in crayon, as long as it contains the sender’s account and routing numbers, and the payee, and the amount. It’s just an instruction note to a bank saying pay this person from this account.

I was told that a long time ago. But it turns out if your routing and account numbers aren't MICR'd, and you in fact hand wrote the entire instrument, it will not work.

(We tried it a couple times at two different banks. With n=2, our p value was < 0.05 :)

Is there some sort of standards document somewhere that outlines the minimum viable check? Because handwritten in crayon on a napkin... I don't think that even "technically" counts. At least not anymore.

But on the other hand, I suppose a payee could accept your Crayola-napkin-check and just punch the numbers into their electronic check submission system?

Interesting. I admit I haven't done it for a while, but I do recall several years ago writing a check out to someone in handwriting (not crayon) and it worked. Might be that recent rules/technology have turned something that used to be true into an urban legend!

Accept now bank will accept this "technically a check". If they can't send it through their reader for scanning, then it will not be accepted. As someone else posted in another comment, the fonts and placement of the information on a check is standardized for ease of automatic reading.

> Why does it need to be connected to your bank at all? It just needs the account, routing, and check numbers.

To prevent fraud

There are numerous outfits that you can go to online to order blank checks. And of the small number that I have used, all of them let me just type in my routing number and account number and other information that appears printed on the check.

Your use of Plaid would exclude me from your service for two reasons:

1: I bank at a small regional credit union that is almost impossible to get linked with Plaid.

2: Plaid hypothetically lets you do a lot more than just learn my account and routing number. I would not trust a new start up with that level of access.

Given that relatively few things require the MICR numbers to be printed with magnetized ink anymore, it’s not clear what fraud someone could commit with your service that they couldn’t commit just as easily commit in a dozen different ways and that we can’t really prevent without a systematic overhaul of the paper check system

I don’t think they mean it prevents fraud in general, I think they mean it prevents fraud on their service specifically.