What is the halacha if someone rented a car service from a goy over a year ago, and now he remembers he forgot to pay the goy at the time. The goy never asked him for the money. Is he still mechuyav to pay or is it just a middas chassidus to pay now.
At this point it would be taus akum, because he should have asked for the money and he didn’t. If it will make a kiddush H-shem and you know who the driver is, then you should pay it if you can, If the driver asks for the money, even if it is later, you will have to pay it, because you really owe it to him.