The only way to answer that question is to be realistic about your industry and your level of knowledge of the law. If you are in an industry that has a lot of complicated issues and you don’t have a sophisticated level of knowledge of the law, you should probably consider hiring a sales tax professional to represent you.
Should I represent myself during a sales tax audit?Audit Defense
Audits can be completely random. The Board has hired statisticians to help them identify taxpayers who are likely underpaying their tax. They can also be generated by tips from the public and they can also be generated from audit leads from other auditors. Say you put an invoice out there to one of your customers and the tax isn’t calculated correctly, an auditor might note that and flag that invoice as a potential audit lead for your account.