The tax-free five

Five states levy no statewide sales tax: Delaware, Montana, New Hampshire, Oregon and Alaska. For checkout flows this makes them a special class of test cases — tax calculators must return zero, and line items should not grow a state-tax row.

If your billing code has a hardcoded tax table, addresses from these five states are exactly the records that will expose stale entries.

Local add-ons still exist

Zero state tax does not always mean zero tax. Alaska allows local sales taxes, and some Montana resort towns add their own. Real-world billing engines read destination-level rules, which is precisely the behavior worth simulating with sample data.

Building a checkout test matrix

A solid matrix pairs one tax-free state address with one high-tax state address (say, Tennessee or Louisiana) and asserts both the computed totals and the displayed tax labels. Our generator's state filter makes assembling such pairs a two-click job.