税务居住资源
Tax Days 发布的所有内容都集中在这里：免费的居住天数计算器、核心指南、规则参考，以及一份用大白话写的术语表。追踪税务居住身份，从这里开始。
核心指南
- US state tax residency, state by stateHow US state tax residency works: the 183/184-day statutory-residence rules, permanent-place-of-abode tests, domicile, and the states that audit hardest. Every state, mapped.
- International tax residency, country by countryHow tax residency works around the world: the 183-day rule and its variants, territorial vs residence-based systems, non-dom regimes, digital-nomad visas, and treaty tie-breakers.
- The types of tax-residency rules, explainedThe handful of rule shapes behind every residency test: simple day counts, the weighted Substantial Presence Test, rolling windows like Schengen, statutory residence with an abode, and facts-and-circumstances.
- The Schengen 90/180 rule, explainedHow the Schengen 90/180 rolling window works for non-EU travelers, what counts as a Schengen day, multiple-passport myths, overstay penalties, and the difference from tax residency.
- US federal tax residency for non-citizensHow the IRS decides if a non-citizen is a US tax resident: the Substantial Presence Test, the green-card test, visa day-counting (F-1, J-1, H-1B), first-year choice, the closer-connection exception, and the exit tax.