# Tax Days

> Tax Days is the first tax residency tracker that combines US federal, US state, and international rules in one beautiful iPhone app. Track your days against the 183-day rule, the Substantial Presence Test, Schengen 90/180, and the UK SRT.

Tax Days is a tax-residency tracker for iPhone built by Parra. The app runs 80+ residency rules across 254 jurisdictions (US states, federal SPT, Schengen 90/180, UK SRT, and 200+ countries) entirely on-device. The web site at https://taxdaysresidencytracker.com provides free calculators, in-depth guides, a complete rules reference, and a glossary.

## Free tools

- [Which calculator do I need? (wizard)](https://taxdaysresidencytracker.com/tools/which-residency-calculator): Two-question wizard that routes to the right calculator.
- [Schengen 90/180 calculator](https://taxdaysresidencytracker.com/tools/schengen-calculator): Rolling-window calculator for non-EU citizens.
- [Substantial Presence Test calculator](https://taxdaysresidencytracker.com/tools/substantial-presence-test-calculator): IRS 3-year weighted formula for non-citizen US tax residency.
- [183-day rule calculator](https://taxdaysresidencytracker.com/tools/183-day-calculator): Configurable calculator for any country or US state.
- [Multi-country day counter](https://taxdaysresidencytracker.com/tools/multi-country-day-counter): Enter trips once; test several jurisdiction thresholds at once.
- [UK Statutory Residence Test calculator](https://taxdaysresidencytracker.com/tools/uk-srt-calculator): Sufficient-ties test for the UK tax year.
- [New York 184-day audit-risk calculator](https://taxdaysresidencytracker.com/tools/nyc-184-day-audit-risk-calculator): Days + abode → statutory-resident determination.
- [FEIE 330-day calculator](https://taxdaysresidencytracker.com/tools/feie-330-day-calculator): Physical Presence Test for the Foreign Earned Income Exclusion.
- [Canada residency calculator](https://taxdaysresidencytracker.com/tools/canada-residential-ties-calculator): Residential-ties + 183-day deemed-resident assessment.
- [Treaty tie-breaker walkthrough](https://taxdaysresidencytracker.com/tools/treaty-tie-breaker): OECD dual-residency cascade (home, vital interests, habitual abode, nationality).
- [Tax year calculator](https://taxdaysresidencytracker.com/tools/tax-year-calculator): Which tax year a date falls in, with tax-year dates by country.

## Pillar guides

- [US state residency](https://taxdaysresidencytracker.com/guides/us-state-residency): The 50-state day-count and abode rules.
- [International residency rules](https://taxdaysresidencytracker.com/guides/international-residency-rules): 183-day rules, territorial systems, non-dom regimes by country.
- [Residency rule types](https://taxdaysresidencytracker.com/guides/residency-rule-types): Day count, weighted SPT, rolling window, statutory residence.
- [Schengen rules](https://taxdaysresidencytracker.com/guides/schengen-rules): The 90/180 rolling window explained.
- [US federal tax residency](https://taxdaysresidencytracker.com/guides/federal-tax-residency): SPT, green-card test, visa day-counting, exit tax.

## Key reference pages

- [All rules](https://taxdaysresidencytracker.com/rules): Searchable reference of all 254 jurisdictions.
- [Glossary](https://taxdaysresidencytracker.com/glossary): 32 tax-residency terms in plain English.
- [Methodology](https://taxdaysresidencytracker.com/methodology): How rule data is sourced and updated.
- [Editorial policy](https://taxdaysresidencytracker.com/editorial-policy): Sourcing, authorship, and update standards.
- [Authors](https://taxdaysresidencytracker.com/authors): Who writes Tax Days, with credentials.
- [Resources](https://taxdaysresidencytracker.com/resources): All calculators, guides, and reference in one place.
- [Pricing](https://taxdaysresidencytracker.com/pricing): Free tier + Pro at $29.99/year.
- [Enterprise](https://taxdaysresidencytracker.com/enterprise): Volume licensing and central reporting for teams and firms.
- [About](https://taxdaysresidencytracker.com/about): Who builds Tax Days.

## Rule types

- [183-day rule](https://taxdaysresidencytracker.com/rules/types/183-day-rule): The 183-day rule is the most common tax-residency threshold worldwide. The full list of countries and US states using it, with each specific threshold.
- [Substantial Presence Test](https://taxdaysresidencytracker.com/rules/types/substantial-presence-test): The Substantial Presence Test is a 3-year weighted day-count formula the US uses for non-citizens: this year in full, a third of last year, a sixth before.
- [Rolling window](https://taxdaysresidencytracker.com/rules/types/rolling-window): Rolling-window rules count days inside a moving window, like 90 days in any 180 for Schengen. The window advances daily, so they are harder to plan around.
- [Statutory Residence Test (UK)](https://taxdaysresidencytracker.com/rules/types/statutory-residence-test): The UK SRT is a three-stage residency test: automatic non-resident tests, automatic resident tests, then a sufficient-ties test using day count plus UK ties.
- [Days + Abode (statutory residence)](https://taxdaysresidencytracker.com/rules/types/days-with-abode): New York, New Jersey, Massachusetts, Connecticut and Pennsylvania trigger statutory residence on 184+ days AND a permanent place of abode. Both are required.
- [Facts and circumstances](https://taxdaysresidencytracker.com/rules/types/facts-and-circumstances): Facts-and-circumstances residency tests weigh the totality of your connections, home, family and business, rather than a fixed day count. California leads.

## Regions

- [US states](https://taxdaysresidencytracker.com/rules/region/us-states): Tax-residency rules for all 50 US states plus DC: statutory residence day counts, permanent place of abode tests, domicile, and how hard each state audits.
- [Europe](https://taxdaysresidencytracker.com/rules/region/europe): European tax-residency rules, including the Schengen 90/180 rule, the UK Statutory Residence Test, and country-specific 183-day rules across 40+ jurisdictions.
- [North America](https://taxdaysresidencytracker.com/rules/region/north-america): Tax-residency rules for the US federal and state tests, Canada's sojourner and significant-ties rules, Mexico's casa habitación test, and the Caribbean nations.
- [Latin America](https://taxdaysresidencytracker.com/rules/region/latin-america): Tax-residency rules across Latin America, including Brazil, Argentina, Colombia, Chile, and Peru: day thresholds, 12-month windows, and territorial regimes.
- [Asia](https://taxdaysresidencytracker.com/rules/region/asia): Tax-residency rules for Asia: Japan's five-year permanent classification, Singapore's 183-day rule, India's financial year, Hong Kong, Thailand, and 30+ others.
- [Middle East](https://taxdaysresidencytracker.com/rules/region/middle-east): Tax-residency rules for the Middle East, including the UAE's 90 and 183-day tests, Qatar, Bahrain, Saudi Arabia, and Israel's multi-year day-count formula.
- [Africa](https://taxdaysresidencytracker.com/rules/region/africa): Tax-residency rules for Africa, including South Africa's physical presence test, Egypt, Nigeria, Kenya, Morocco, and 30+ more day-count and domicile rules.
- [Oceania](https://taxdaysresidencytracker.com/rules/region/oceania): Tax-residency rules for Australia's four alternative residency tests, New Zealand's 183-day and permanent place of abode rules, and the Pacific island nations.

## Personas

- [For digital nomads](https://taxdaysresidencytracker.com/for-digital-nomads): Schengen 90/180, 30+ country rules, SPT, UK SRT.
- [For snowbirds](https://taxdaysresidencytracker.com/for-snowbirds): NY 184-day, Florida domicile, audit defense.
- [For expats](https://taxdaysresidencytracker.com/for-expats): FEIE, SRT, treaty tie-breakers.
- [For remote workers](https://taxdaysresidencytracker.com/for-remote-workers): Convenience-of-employer, multi-state nexus.
- [For CPAs & accountants](https://taxdaysresidencytracker.com/for-cpas-accountants): Audit-ready records and multi-client tracking.
- [For green-card holders](https://taxdaysresidencytracker.com/for-greencard-holders): SPT, green-card test, FBAR/FATCA.
- [For international students](https://taxdaysresidencytracker.com/for-international-students): F-1/J-1 exempt years, OPT, Form 8843.
- [For crypto traders](https://taxdaysresidencytracker.com/for-crypto-traders): Residency-driven capital gains, the NRA 30% trap.
- [For dual citizens](https://taxdaysresidencytracker.com/for-dual-citizens): Treaty tie-breakers and the US saving clause.
- [For retirees](https://taxdaysresidencytracker.com/for-retirees): Social Security, Medicare IRMAA, home-state domicile.

## Comparisons

- [How Tax Days compares (all comparisons)](https://taxdaysresidencytracker.com/vs)
- [Tax Days vs. Monaeo](https://taxdaysresidencytracker.com/vs/monaeo)
- [Tax Days vs. TaxBird](https://taxdaysresidencytracker.com/vs/taxbird)
- [Tax Days vs. Domicile365](https://taxdaysresidencytracker.com/vs/domicile365)
- [Tax Days vs. Topia](https://taxdaysresidencytracker.com/vs/topia)
- [Tax Days vs. iReside](https://taxdaysresidencytracker.com/vs/ireside)
- [Tax Days vs. a spreadsheet](https://taxdaysresidencytracker.com/vs/spreadsheet)

## Blog (most recent)

- [Mexico tax residency: home, center of vital interests, and 183 days](https://taxdaysresidencytracker.com/blog/mexico-183-day-rule): Mexico determines tax residency primarily by 'casa habitación' (home) and center of vital interests. Day counts matter for the 50% income test under treaties.
- [SPT exempt individuals: students, teachers, and the day-count exclusions](https://taxdaysresidencytracker.com/blog/spt-exempt-individuals): The IRS Substantial Presence Test lets certain visa categories, students (F, J, M, Q), teachers and trainees, and others exclude their US days entirely.
- [Italy tax residency: 183 days, registered residence, and the impatriate regime](https://taxdaysresidencytracker.com/blog/italy-183-day-rule): Italy treats you as a tax resident if you're registered there, have your habitual abode there, or spend 183+ days. Plus the impatriate regime for workers.
- [Japan tax residency: non-permanent, permanent, and the 5-year clock](https://taxdaysresidencytracker.com/blog/japan-resident-classification): Japan classifies foreigners as non-resident, non-permanent resident, or permanent resident, each with different tax exposure. The 5-year rule is the key.
- [Singapore tax residency: 183 days, the qualifying employee rule, and rates](https://taxdaysresidencytracker.com/blog/singapore-183-day-rule): Singapore taxes residents at 0–24% with no capital gains tax. Residency is based on the 183-day rule plus a qualifying-employee test. Here's how to track it.
- [What records do you need for a residency audit? A complete checklist](https://taxdaysresidencytracker.com/blog/residency-audit-records-needed): State and federal residency auditors want very specific records. Here's the complete list of what they ask for, what you should keep, and how long to keep it.
- [France tax residency: domicile, 183 days, and center of economic interest](https://taxdaysresidencytracker.com/blog/france-183-day-rule): France uses three alternative tests: habitual residence, professional activity, and center of economic interest, plus a 183-day rule under its treaties.
- [Canada tax residency: significant ties, 183-day rule, and departure tax](https://taxdaysresidencytracker.com/blog/canada-residency-days-ties): Canada determines tax residency by significant residential ties, with a 183-day backstop. How the CRA applies it, and what departure tax means for emigrants.
- [The Best Facebook Groups for US Expats and Digital Nomads](https://taxdaysresidencytracker.com/blog/best-facebook-groups-for-expats-and-nomads): Four active Facebook groups for US expats and digital nomads, what each one is good for, and why residency and day-count questions never belong in a thread.
- [Tax Relief for Impatriates: Special Regimes for New Residents](https://taxdaysresidencytracker.com/blog/impatriate-lump-sum-tax-regimes): Impatriate regimes, lump-sum taxation and non-dom status all cut the tax bill of someone who moves in. How Italy, Switzerland, Spain and Malta differ.
- [The Cyprus 90-Day Rule: Why It Is Not the Schengen 90/180](https://taxdaysresidencytracker.com/blog/cyprus-90-day-rule-vs-tax-residency): Cyprus is in the EU but not in Schengen, so its 90-day visitor limit is separate and days there do not count against Schengen. How 90, 60 and 183 differ.
- [Australia tax residency: 183-day rule, domicile test, and the resides test](https://taxdaysresidencytracker.com/blog/australia-183-day-domicile): The ATO uses four tests for Australian tax residency: resides, domicile, 183-day, and superannuation. Here's how each works for expats and Australians.
- [Contemporaneous evidence: what residency auditors actually accept](https://taxdaysresidencytracker.com/blog/contemporaneous-evidence-auditors): Auditors distinguish contemporaneous records, created at the time, from reconstructed ones created later. Here's what actually counts as contemporaneous.
- [Treaty tie-breaker rules: when two countries claim you, who wins?](https://taxdaysresidencytracker.com/blog/treaty-tie-breaker-rules): If two countries both claim you as a tax resident, the treaty tie-breaker decides. How the OECD model applies: permanent home, vital interests, abode.
- [Defending a residency audit: timeline, evidence, and what auditors actually do](https://taxdaysresidencytracker.com/blog/defending-residency-audit-guide): State residency audits target high earners who claim to have left. What to expect, the timeline, the evidence requests, and how to defend your domicile.
- [Substantial Presence Test vs. Green Card test: how the two trigger US tax residency](https://taxdaysresidencytracker.com/blog/spt-vs-green-card-test): Non-citizens become US tax residents under either the Substantial Presence Test or the Green Card test. How each works, and what happens when both apply.
- [Ireland tax residency: 183 days, the 280-day rule, and ordinary residence](https://taxdaysresidencytracker.com/blog/ireland-tax-residency-rules): Ireland uses a 183-day rule and a two-year cumulative 280-day rule, plus ordinary residence and domicile. How the four interact for inbound residents.
- [Form 8840 and the closer-connection exception](https://taxdaysresidencytracker.com/blog/closer-connection-exception): Even if you meet the IRS Substantial Presence Test, you can avoid US tax-resident status by claiming closer connection on Form 8840, if you qualify for it.
- [The SPT 3-year weighted formula, with worked examples](https://taxdaysresidencytracker.com/blog/spt-three-year-weighted-formula): The IRS Substantial Presence Test uses a 3-year weighted day-count formula. Here it is in plain math, with worked examples for visas and travel patterns.
- [Tax Days vs. Topia: a comparison for individual cross-border residents](https://taxdaysresidencytracker.com/blog/tax-days-vs-topia): Topia is enterprise mobility software for global employers. Tax Days is for individuals. Here's why the comparison matters and which is right for you.
- [The remote worker's multi-state tax guide: nexus, day counts, and double tax](https://taxdaysresidencytracker.com/blog/remote-worker-multi-state-tax): Working remotely from several states triggers nexus, withholding, and potential double taxation. How to track days and avoid a surprise state tax bill.
- [Tax Days vs. Domicile365: feature, price, and privacy comparison](https://taxdaysresidencytracker.com/blog/tax-days-vs-domicile365): Domicile365 is a long-running residency tracker for snowbirds and cross-border workers. Tax Days is the iPhone-native alternative. Here's how they compare.
- [Pennsylvania residency rules: domicile, statutory residence, and Philly's local tax](https://taxdaysresidencytracker.com/blog/pennsylvania-domicile-residency): Pennsylvania has a 3.07% flat tax, but Philadelphia adds a 3.75% city wage tax. How domicile, statutory residence, and local tax interact for leavers.
- [Tax Days vs. iReside: which residency tracker is right for you?](https://taxdaysresidencytracker.com/blog/tax-days-vs-ireside): iReside and Tax Days both target privacy-conscious, internationally mobile users. An honest comparison on price, tracking method, coverage and privacy.
- [Illinois residency rules: domicile, the abode test, and Chicago tax exposure](https://taxdaysresidencytracker.com/blog/illinois-residency-rules): Illinois taxes residents at a flat 4.95%, and the move to Florida is popular among Chicago-area professionals. How Illinois residency rules really work.

## Per-jurisdiction rule pages

Every jurisdiction has its own page at https://taxdaysresidencytracker.com/rules/[code]. Examples:
- [Alaska](https://taxdaysresidencytracker.com/rules/us-ak): 🏔️ tax residency rules
- [Alabama](https://taxdaysresidencytracker.com/rules/us-al): 🌾 tax residency rules
- [Arkansas](https://taxdaysresidencytracker.com/rules/us-ar): 💎 tax residency rules
- [Arizona](https://taxdaysresidencytracker.com/rules/us-az): 🌵 tax residency rules
- [California](https://taxdaysresidencytracker.com/rules/us-ca): 🐻 tax residency rules
- [Colorado](https://taxdaysresidencytracker.com/rules/us-co): ⛰️ tax residency rules
- [Connecticut](https://taxdaysresidencytracker.com/rules/us-ct): 🍂 tax residency rules
- [Delaware](https://taxdaysresidencytracker.com/rules/us-de): 🏛️ tax residency rules
- [District of Columbia](https://taxdaysresidencytracker.com/rules/us-dc): 🏛️ tax residency rules
- [Florida](https://taxdaysresidencytracker.com/rules/us-fl): 🌴 tax residency rules
- [Georgia](https://taxdaysresidencytracker.com/rules/us-ga): 🍑 tax residency rules
- [Hawaii](https://taxdaysresidencytracker.com/rules/us-hi): 🌺 tax residency rules
- [Iowa](https://taxdaysresidencytracker.com/rules/us-ia): 🌽 tax residency rules
- [Idaho](https://taxdaysresidencytracker.com/rules/us-id): 🥔 tax residency rules
- [Illinois](https://taxdaysresidencytracker.com/rules/us-il): 🏙️ tax residency rules
- [Indiana](https://taxdaysresidencytracker.com/rules/us-in): 🏎️ tax residency rules
- [Kansas](https://taxdaysresidencytracker.com/rules/us-ks): 🌻 tax residency rules
- [Kentucky](https://taxdaysresidencytracker.com/rules/us-ky): 🐎 tax residency rules
- [Louisiana](https://taxdaysresidencytracker.com/rules/us-la): ⚜️ tax residency rules
- [Massachusetts](https://taxdaysresidencytracker.com/rules/us-ma): 🦞 tax residency rules
- ...and 234 more.

## Crawl guidance

- Full sitemap: https://taxdaysresidencytracker.com/sitemap.xml (machine-readable) and https://taxdaysresidencytracker.com/sitemap-html (human-browsable).
- The free calculators run entirely client-side and don't require sign-in.
- All blog posts and reference pages are publicly accessible without account.
- Tax Days is general information, not tax advice. Anyone making real tax decisions should consult a qualified tax professional.