Share your insights or perspective on the financial matter presented in the input.

Should I charge my children interest when they borrow money? 
This is largely a cultural issue. I would be appalled at the very idea that my parents would charge me interest for lending me money. Just as they would be appalled if I were to do so if lending them money. I find the idea of attempting to make money off of your children fundamentally wrong.  I realize that you only want to do this to teach them, that you have their best interests in mind and not your own profit. Nevertheless, what will actually happen were you to charge them interest is that you would accrue a monetary gain at the expense of your children. Is that really something you would be comfortable with? Now, as I stated at the beginning, this is clearly a cultural issue. Based on the other answers here, many cultures, probably including your own, find nothing wrong with this. I've even heard of people charging their adult children rent when they come home for the holidays, something that is completely baffling to me.  The point I am trying to make is that asking other people's opinions on whether you should do this is not very useful unless those people share your own cultural background. My family and culture are such that the idea of charging interest to one's family members seems downright immoral to me. Given that you are asking here, it seems like you might be on the fence about it yourself. However, I freely admit that my answer is colored by my own cultural prejudices and may very well not be applicable to you.  Still, ask yourself, is a relatively small amount of money in the grand scheme of things—or, for that matter, an entire fortune—worth jeopardizing your relationship with your children? Do you really believe that having their parents retroactively charge them interest for a loan will somehow teach them something about the "real world" that your already adult children don't know? One of the main reasons they came to you and didn't go to a bank is precisely that they expected the loan to be interest free.  So, sure, tell them that you won't lend any more until they repay what they owe. Even better, sit them down and have an honest, adult conversation, explaining that the absence of the money they owe is making itself felt in your household and work out a way they can repay you.  What, in my opinion, you most certainly shouldn't do is treat your relationship with your children as a regular business transaction. It isn't and I am sure you don't want it to be.