As a seller, you are responsible for collecting and remitting the correct amount to the state. If you do not collect from the customer or collect the wrong amount, you will owe any additional tax, plus you may be assessed penalties and interest.
The main reason this happens is the business owner believes that their product or sale is nontaxable. So do your own research in advance. Go to the Texas website (www.window.state.tx.us/taxinfo/sales/), call your tax advisor or give your local sales tax office a call.
Like any good CPA, I need to add a disclaimer. Unfortunately, it is impossible to offer comprehensive tax info over the Internet, no matter how well researched or written. And remember, I love my readers, but having me bookmarked on your computer doesn’t make you a client. Before relying on any information given on this site, contact a tax professional to discuss your particular situation.