UK and US address formats, tax-free-state playbooks, and form-filling guides — realistic test addresses explained for QA and developers.
A UK postcode looks random — SW1A 2AA — but every position has a job: area, district, sector, unit. The six valid formats, the rules inside each position, and how forms actually validate them.
Read full article →UK billing fields differ from US ones — no state, county optional, postcode last — and card checks only look at the house number and postcode. Field-by-field guide, the US-to-UK mapping, and the five most common rejections.
Read →People search "UK tax free address" expecting a British Delaware. There isn't one: UK prices already include VAT, visitor VAT refunds ended in 2021, and the Channel Islands aren't UK. What the phrase actually means, and what to use instead.
Read →Alaska, Delaware, Montana, New Hampshire, and Oregon levy no state sales tax. State-by-state fine print, which one to pick for test data, and the pitfalls.
Read →No state sales tax, no local add-ons, one area code statewide, and the highest address occurrence rate in commercial systems — why DE is the safe default.
Read →When your test persona lives near California or Seattle, an Oregon address is the geographically believable choice. Cities, ZIP and area codes, and common mistakes.
Read →The other three sales-tax-free states all carry a footnote — resort taxes, meals & rooms tax, municipal add-ons. Where the footnotes are and how to route around them.
Read →"Tax-free state" can mean no sales tax or no income tax — two different lists. Why WA, TX, and FL keep getting mislabeled, and how to check a state in seconds.
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