Borrowed Something From a Neighbor? The Halachic Rules of Paying It Back

You borrowed a cup of laundry detergent from your neighbor and now want to return it. However, you normally use a more expensive brand. Are you permitted to return a cup of your own detergent, even though it costs more?

The following halachic guidelines, based on the book Brit Pinchas by Rabbi Pinchas Wind, explain when it is permissible to return a more expensive product and when doing so may raise a concern of interest.

1. Returning a More Expensive Product

If someone borrows a small quantity of an inexpensive product but normally uses a more expensive brand of the same type, they may return an equivalent quantity of the more expensive product if purchasing the cheaper version would leave them with a surplus they have no use for.

The reasoning is that the additional value is not being given as compensation for the loan, but rather to avoid the unnecessary expense of purchasing a product that would otherwise go unused.

Examples:

Laundry detergent: A woman borrows a cup of laundry detergent from her neighbor, who uses an inexpensive brand. Since she normally uses a more expensive brand, she may return a cup of her own detergent rather than purchase an entire package of the cheaper product and be left with an unusable surplus.

Diapers: A woman borrows several diapers from her neighbor, who uses a less expensive brand. If she normally uses a more expensive brand, she may return the same number of diapers from the brand she uses. She is not required to purchase an entire package of the cheaper brand when she has no need for the remaining diapers.

2. Returning an Entire Package

If someone borrows a full, unopened package of an inexpensive product, they may not return a more expensive package in its place, even if the more expensive brand is the one they regularly use.

In this case, the borrower can purchase an identical package of the less expensive product and return it in full. Since there would be no leftover product going unused, the reasoning behind the previous leniency does not apply.

3. Returning a Lower-Quality Product in a Larger Quantity

If someone borrows a product and wishes to return a similar item of lower quality, they may add a small amount to compensate for the difference in value. As long as the total value of the returned product is equal to the value of what was originally borrowed, the additional quantity is not considered interest.

Example: A woman who borrows a package of high-quality baby wipes from her neighbor may return a larger quantity of lower-quality wipes, provided their combined value is equivalent to that of the original package.