My wife and I don’t have children. We moved into a new apartment where the past tenants had a hanacha (reduction) from the water company for their baby. We just got our bill, and it says that we are still paying a reduced rate on account of the baby. Am I obligated to return the money due to the water company?
Answer:
In principle, because they water company has clearly made a mistake (they did not intend to give you a “gift”), it follows that you have to pay the full amount. You should notify the water company of their error, and leave it to them — if they wish, they will claim the extra amount from you, which they can add to your next bill. You do not need to do more than this.
Sources: See Bava Metzia 64a; Shulchan Aruch; Choshen Mishpat 232:1; the extra money is considered an aveida, and it is therefore sufficient to notify the water company of the mistake.
