My kid spent all their business money, should I step in?

The instinct is a savings rule. Half goes in the bank, effective immediately. It is a reasonable instinct and it usually backfires, because a rule imposed on their money quietly reclassifies it as your money with conditions attached, and the ownership was the point.

If it is their business, the money is theirs, including the eighty dollars that went on something you find ridiculous. Spending money badly is the only way anyone learns what money is worth, and eighty dollars at thirteen is the cheapest that lesson will ever be. At twenty three it costs considerably more.

The real problem is usually different from the one that upset you. They did not just spend their profit, they spent the float. Now there is no money for gas, or supplies, or the thing that gets replaced when it wears out, and the business cannot run until somebody funds it.

That is the lesson worth naming, and it has a name: the business needs money to keep operating, and that money is not profit. Separate the two pots out loud. This much stays with the business so it can run. What is left over is yours and nobody gets a vote on it.

This lands far better after they have hit the wall than before. Told in advance it is a lecture. Discovered on a Saturday when there is no gas, it is arithmetic they will remember.

Then hold the line on the important part. Do not replace the money. If there is no float, the business pauses until the next job funds it, which is uncomfortable for about a week and permanently instructive.

The one thing worth intervening on is not the spending at all. If your kid cannot tell you roughly what came in and what went out, that is a bookkeeping gap rather than a discipline problem, and it is easy to fix. A kid who knows the numbers and spends it all has made a choice. A kid who does not know the numbers cannot make one.