Sales tax isn't your money. You collect it from your customers and send it in for them. If you are required to charge sales tax, you need to create procedure to track this money and not spend it. Missing reports are caught quickly (at least in Kansas) and if you don't sent the report as requested the state may "estimate" your sales for you. If you don't make payments on time, you risk an audit of not only your sales tax liabilities but your compensating use tax liabilities. (Comp use is the sales tax on your internet and phone purchases where no sales tax is collected because the company doesn't have a presence in that state. In this case, the seller doesn't collect it from you so you are expected to pay it yourself. There has been a lot of talk, lawsuits, and legislation on this issue but you still pay it.)
So, you need to work out some procedure for saving sales tax you collect back and not spending it. And get the reports and payments in on time.