California does not impose sales tax on services, such as child care. If you are subject to some other local tax, there are two ways to handle it:
1. Include the tax paid, by the parents, in your revenue. Then, deduct the tax remitted to the authorities as a business expense. It comes out even.
2. Keep a separate account for sales tax and not include either it as either receipts or expenses on your Schedule C.
If your question is should you do an itemized charge to your clients for taxes posed on your business: that's business decision, not a tax question. I would choose to include it in the tuition fee, and then deduct the tax payment, to the authorities, as an expense.
