Why this matters
Sales tax is money you collect for the state, get it wrong and you owe the tax anyway, plus penalties. Since the Supreme Court's Wayfair decision in 2018, you can owe tax in states you have never set foot in. QuickBooks can calculate rates automatically, but only after you tell it where you are registered.
What "done" looks like
- You know where you have nexus: physical presence plus any economic-nexus states
- You are registered before collecting
- Sales tax is on in QuickBooks with the right agencies and filing frequency
- Products and services are correctly marked taxable or exempt
How to do it
- Determine nexus first. Physical presence generally creates nexus, subject to state-specific rules; many states add economic nexus around $100,000 in annual in-state sales.
- Register with each state's tax agency before collecting; collecting unregistered is illegal in most states.
- Turn on sales tax in QuickBooks (Taxes → Sales tax) and add each agency with your filing frequency.
- Set product and service taxability so exempt items (many services, resale goods) are taxed correctly.
- Keep customer addresses accurate, rates are calculated by location.
- File on calendar, even at $0, states penalize missing returns.
Common mistakes
- Collecting tax before registering, or registering nowhere and hoping
- Assuming services are never taxable, many states tax services
- Skipping $0 returns because "there was nothing to remit"
Real-world examples
- South Dakota v. Wayfair (2018) let states tax remote sellers; most then adopted economic-nexus thresholds, commonly $100,000 in sales, why online sellers track revenue by state.
- QuickBooks Online's automated sales tax computes rates from the customer address and product category and tracks what you owe per agency. Registration stays on you.
From a founder's point of view
Sales tax is the liability that grows silently, every untaxed sale in a nexus state is future margin at stake. An hour of setup turns an open-ended risk into a routine the software mostly runs.
Rule of thumb
Registered, then collecting, then filing on calendar, in that order, in every state where you cross a threshold.
