Halocho #1448 - 0% interest on loans

The Torah prohibits charging interest and paying interest to fellow Jews. The Torah allows charging interest and paying interest to non-Jews.

A person who lends money to a Jew and charges interest, has transgressed six Torah commandments and - if he doesn't repent - will not awaken at Techiyat Hameitim - when the dead will be revived at the End of Days.

The person who borrows the money transgresses three Torah commandments.

The scribe, witnesses, co-signer and middle-man all transgress one Torah commandment.

In most cases, a person who received interest from a loan needs to return it. Even if the borrower - on his own accord - returns more than he borrowed or adds a gift, it is considered interest on the loan and the lender is not allowed to accept it. Even non-monetary gain from a debtor is forbidden. For example:

The creditor may not ask the debtor to inform him when somebody has arrived, unless he used to do this before giving him the loan.

The debtor may not go out of his way to greet the creditor, unless he always used to do so.

The debtor may not patronize the creditor's business, unless he used to do so before getting the loan.

When doing a business deal with a fellow Jew, one needs to use a Heter Iska - the subject of a future posting.

Source: Kitzur Shulchan Aruch 65:1, 2, 4, 5, 9, 10

Please daven for 3 year old נָעֳמִי בַּת דִינָה who is being treated for lymphoma