I laid out money for a few people to purchase an item and they paid me back the money. I ended up returning the item for them (and I received the refund), and ordered a different one for them which was a few dollars less. For example, if the new item cost $6.82 less than the original and I now need to split the money to 3 people, which comes out to $2.2733 to each person for which there is no coin to pay this exactly.
Can I round up and give each $2.28, etc. or is there problem of ribbis to pay them more (meaning, when I receive the refund and am holding the extra money that I need to return to them – is that considered like a loan to me from them)? I would prefer not to ask each person to be mochel the fraction of a coin.
[also, if there would be an issue to round up in the above case, what about if the amount is, for example, $2.275 for each person?]
If the amount comes out to $2.273 then it is usually rounded down to $2.27, therefore you can give them back only $2.27, not $2.28, and there is no need to ask them mechila, because this is what is done in stores etc. If, however the amount would be $2.275, then you should round it off to $2.28. Although when returning products, people are not particular about the exact amount that they receive, however when it comes to money people are particular. For example, when lending someone half a cup of sugar, we are not particular to receive back the exact number of grams that it weighs, however when getting change in the store, we will want to get exact change.
Minchas Yitzchok 9-88 discusses a case where the person gives a little bit extra money because he doesn’t have change, and it is difficult for him to go thru the bother to get change in order to give the person the exact amount. Then we say that it is given as a gift in order to save oneself from the hassle. In our case however, the person does have change, and he only wants to know which one to give. He should not give the extra amount, since ribbis even applies to an amount less than a pruta. Also see Nesivos Shalom 1604 (8), and Chelkas Binyomin 160-33.