Sales tax has a reputation for being confusing, and honestly, that reputation is earned — the rules vary by state, by product or service type, and sometimes by county or city on top of that. Most of the mistakes small business owners make aren't about math. They're about not knowing a rule existed in the first place.
Do you even have to collect it?
This comes down to nexus — the connection between your business and a state that creates a tax obligation there. Having a physical location, employees, or inventory in a state almost always creates nexus. Selling remotely into a state above a certain revenue or transaction threshold can create economic nexus too, even without a physical presence there.
Not everything you sell is taxable
Physical goods are usually taxable. Services are a mixed bag — taxable in some states, exempt in others, and taxable only in specific circumstances in a handful more. Digital products fall into their own patchwork of rules. Assuming a category is exempt because it "feels like a service" is one of the more common — and expensive — mistakes.
Collecting it is only half the job
Sales tax you collect isn't your money — you're holding it for the state until you file and remit it. Filing frequency (monthly, quarterly, or annually) is usually assigned based on your sales volume, and missing a filing deadline typically triggers penalties even if you didn't actually owe anything that period.
Where this usually goes wrong
- Not registering before you start collecting — you generally need a permit in place first, not after.
- Applying one rate everywhere — rates can vary by county or city, not just by state.
- Losing track of exemption certificates — a tax-exempt sale without documentation on file can turn into a tax liability during an audit.
Sales tax pairs closely with the rest of your obligations — if tax season prep already feels like a lot, it's worth handling both together rather than separately.
If you want a quick estimate of what you should be collecting on a given sale, our free sales tax calculator is a good starting point. For the ongoing filing and remittance — the part that actually causes penalties when it slips — S&C Bookkeeping handles that as part of our tax-ready bookkeeping. Reach out if you're not sure where your business currently stands.