Legal Question in Construction Law in California

I hope you didn't collect more than $500, because the legal limit on deposits for home improvements is 10% or $500 whichever is LESS. There is also a statutory cooling off period for home improvement contracts. I don't do a whole lot of home improvement litigation so I'm not sure what the period is off the top of my head, but if it is 4 days or more, she had the right to cancel. You should know this, by the way, if you are a licensed contractor. Which brings me to the next point. If you aren't licensed you have no case. Now, assuming your deposit was legal, she was outside the cooling off period, and you are licensed, you don't need to cite code sections. Just go to the Judicial Council's website to the "Forms" tab, and fill out the breach of contract complaint forms. Bear in mind, however, that you will have an uphill battle proving you would have made a profit on the job. I've had clients pay tens of thousands of dollars to claims consultants trying to prove their lost profits on major construction jobs. It won't be much easier for you, but for less money.