Not every expensive mistake feels like a mistake. Some of them feel like doing the paperwork properly.

Here are three that cost families real money every single year, and none of them involve doing anything you'd recognize as wrong at the time.

One. Putting money in the wrong column.

I've written about this before and I'll keep writing about it: assets in your kid's name are assessed far more harshly than assets in yours.

The mistake here isn't strategic, it's clerical. On the forms, parent assets and student assets are separate questions, and it is genuinely easy to put a number in the wrong one when you're forty minutes into a long form on a weeknight.

That slip can cost thousands of dollars a year. Slow down at those two boxes.

Two. Reporting things that aren't supposed to be there.

If you include your retirement accounts or your primary residence in your net worth on the FAFSA, you have just volunteered money out of your own pocket.

They don't belong there. Nobody is trying to tric...