When making bank deposits, does one have to filter out foreign coins if the bank itself doesn't?

Question

Where I live, one can go to any bank and buy rolls (or cases!) of pennies, and one can also redeem such rolls. Merchants do both of these often.

I have noticed that rolls of pennies occasionally contain foreign currency of similar size and appearance. I'm in the US and we see Canadian pennies sometimes; presumably they're mixed into the general money supply and often people don't notice them. I don't know what procedures banks use to check/validate the rolls of coins they distribute, but I assume it doesn't involve anybody inspecting individual coins and is probably based on weight and length.

My question is: if you have a large number of pennies that you want to deposit, does halacha require that you inspect them all first and weed out any foreign ones, or does the fact that the banks don't seem to do this either mean that that's just a risk we all take? Does the answer depend on likelihood, for example one who just took a trip to Canada and has a pocketfull of change has to check but in general people don't?

This question was prompted by a project in my synagogue's school to collect 304,805 pennies as part of writing a new sefer torah. I'm asking out of curiosity, not as a decision-maker for those deposits.

Answer 1

I don't think it's a full answer, but here is a source that IMHO should be considered:

משנה בבא בתרא פרק ו משנה ב

המוכר פירות לחבירו הרי זה מקבל עליו רובע טנופת לסאה תאנים מקבל עליו עשר מתולעות למאה מרתף של יין מקבל עליו עשר קוססות למאה הקנקנים בשרון מקבל עליו עשר פיטסות למאה:

Mishna Baba-batra 6:2

One who sales fruits to another, [The buyer] accepts rova filth (rotten fruit) for each Sea'a, for figs - [the buyer] accepts ten wormed figs for every hundred figs. [For] A basement of wine [the buyer] accepts ten poor quality jugs for every hundred jugs. In the Sharon area, [The buyer] accepts ten unprepared jugs for every hundred jugs.

So, if the bank "buys" those coins from you, it could be that it accepts a reasonable amount of wrong currency, if it's a big amount of coins, because "that's the way of the traders" - not to be peaky about it.

Now, I understand that there is difference between coins an fruits - coins do not rot, but not always a difference in the reality will cause a difference of ruling.

Answer 2

I offer this incomplete answer as a contribution to developing a better answer.

Rambam Hilchos Genevah, 1 (2) states:

The Torah prohibits stealing even the slightest amount. It is forbidden to steal as a jest, to steal with the intent to return, or to steal with the intent to pay. All is forbidden, lest one habituate oneself to such conduct.

So if the value of the foreign coin is less than the regular one, one is prohibited from making a substitution. How careful one has to be must depend on the size of the risk.

On the other hand, we may find a way out by looking at the halachic approach to bankruptcy. Rabbi Yitzchok A. Breitowitz's article says in part,

there is no mechanism in halakhah that is tantamount to escaping your debts by filing a bankruptcy and obtaining a discharge

Some opinions say that to invoke a bankruptcy discharge is theft; since under Jewish law you still owe that money, not paying it back is illicit. Other opinions say that even though halakhah does not recognize a bankruptcy discharge in a pure halakhic system, under the system that we live in one is permitted to utilize it.

There is yet another theory that would allow the same thing, and that is what I would call the "rules of the game" theory. If I lend you money and am aware of the fact that under American law there are escape mechanisms, in effect, I have agreed to put myself in that system.

According to this "rules of the game" principle, it may be an accepted part of doing business that foreign coins find their way into these rolls and one does not have to worry.