SInce this year is a shemitah year, we will take a break from the Chayei Adam to discuss the halachos of pruzbol.
One of the issurim in the Torah related to shemitah is the issur to collect a debt. According to most rishonim, this issur takes effect at the end of the shemitah year, at the last moment of Elul. Thus, all debts are canceled when we begin the new year following shemitah. In the same way that shemitah releases the land from usage, it releases debts as well. We will clarify how the shemitah process cancels loans, and how the pruzbol allows for their collection.
The types of debts canceled by the shemitah process are specifically loans in which one person borrowed from another. The Torah writes the prohibition as lo yigos, he shall not approach the borrower for the debt. If the Shimon, the borrower, wishes to pay, the Reuvain, the lender, must tell him meshameit ani, that he is keeping shemitah, but if the borrower insists on paying, he may accept it. However, Reuvain may not ask for the debt.
We learn from here that if Reuvain cannot ask for the debt anyways, such as a debt which is not yet due for collection, the debt is not canceled. Since it is not yet due, it cannot be asked for, so it does not get canceled.
Taking it a step further, we need to discuss purchases on merchandise and workers owed wages. The Mishnah gives a case of merchandise purchased on credit, such as a tab at the grocer, until the grocer eventually sends a bill to the customer. If the bill is sent before the shemitah year, the money is a debt ready to be paid, so shemitah cancels it. However, as long as it is on the tab, and the grocer has not asked for it, it does not get canceled.
Similarly, regarding a worker who is paid for a job, such as a plumber or electrician, if they are still in the middle of the job, the debt is not canceled, as it is not yet collectable. If the job is finished before the end of shemitah, and the standard is that the worker is due to be paid immediately, the debt is due, so shemitah would cancel it and the worker cannot collect it.
Another similar situation is a salaried worker who is paid on a weekly or monthly basis. The question will affect the last pay period of the previous year. If the pay period does not end until after shemitah, they may collect that month’s salary, since it was not yet collectable until after shemitah. However, if the pay period ended before shemitah, and the employer did not yet pay before Rosh Hashanah the debt is canceled through shemitah.
We see that shemitah has the ability to cancel not only debts from a loan, but debts from other obligations as well. This becomes relevant in many ways, including tutoring or selling something, and not only when lending money.
Summary
Shemittah cancels any debts from obligations in which the debt is due to be paid up before Rosh Hashanah.