Know your days. Own your residency.
183333 is a free lab for people who live, work and invest across borders. Track every day you spend in every country, test yourself against real residency rules, and get matched with an expert when two countries want the same income.
Four numbers that keep mobile people out of trouble
Our name is our method. Every tool and guide on this site maps to one of these four disciplines.
Know the threshold
…and the window. Calendar year, fiscal year or rolling 12 months — and whether it is really 180, 182 or no day test at all.
Years of look-back
The US weights three years. Audits reach back further. Keep a continuous three-year view of your days.
Tests, not one
Days, home, and centre of interests. Passing the day test alone rarely settles residency.
Proofs per stay
Travel record, lodging record, payment record. Three independent proofs make a log audit-ready.
Answers in seconds, not billable hours
Every calculator runs in your browser. Nothing to install, no account, no data stored on our servers.
Multi-country Day Tracker
Log trips once. See days per country by calendar year or rolling 365 days, Schengen days left and US weighted days — then export CSV.
US Substantial Presence
The IRS three-year weighted formula with exempt days and the exact number of days you have left.
Schengen 90/180
Days used, days left and the longest stay you can take from any entry date.
UK Statutory Residence
Automatic tests and the sufficient-ties table for leavers and arrivers.
India Residential Status
Resident, RNOR or NR — with the 120-day and deemed-resident rules.
Days-Left Planner
Test a planned trip against any threshold and see the exact date you would cross it.
Not every country counts to 183
Same idea, very different rules. A snapshot from our database:
Thailand — calendar year
India — 1 Apr to 31 Mar
UK — days a leaver with 4 ties can be resident on
Mexico — no day test; home decides
Two countries might be claiming you?
Tell us your situation once. We route it to a vetted cross-border tax or relocation professional who fits your countries, language and budget. No cost to you, no obligation.
Typical reply: 1–2 business days.
Plain-English guides, written to be checked
Each guide names its official source and is reviewed on a schedule.
The 183-Day Rule, Explained Without the Myths
What the 183-day rule really is, where it comes from, how days are counted, and why staying under 183 days does not automatically keep you out of a country's tax net.
9 min read →United StatesThe US Substantial Presence Test, Step by Step
How the IRS three-year weighted formula works, which days are excluded, worked examples, and the closer-connection exception.
8 min read →United KingdomThe UK Statutory Residence Test: Days, Ties and Traps
How HMRC decides UK tax residency: automatic overseas tests, automatic UK tests, and the sufficient-ties table that can make you resident on as few as 16 days.
9 min read →VisasSchengen 90/180: How the Rolling Window Really Works
The Schengen short-stay rule for non-EU visitors, how to count the rolling 180-day window, and why it is different from tax residency.
7 min read →TreatiesResident in Two Countries? How Treaty Tie-Breakers Decide
How the OECD-model tie-breaker ladder (permanent home, vital interests, habitual abode, nationality) resolves dual residency, and what to document.
8 min read →RecordsHow to Prove Where You Were: A Day-Count Evidence Kit
What tax authorities accept as evidence of physical presence, how to build an audit-ready log, and a monthly routine that takes five minutes.
7 min read →Nomads12 Tax Residency Mistakes Digital Nomads Make
The recurring errors that create surprise tax bills for remote workers — from never leaving home-country residency to forgetting state rules.
8 min read →United StatesUS State Residency: The 183-Day Rule Inside the States
How states like New York and California use domicile and statutory-residence tests, why day counts matter for snowbirds and remote workers, and how to document a move.
7 min read →IndiaIndia Residential Status for NRIs: 182, 120 and 60 Days
How India decides Resident, RNOR and Non-Resident status, including the 120-day rule for high-income visitors and the deemed-resident rule.
8 min read →CanadaCanadian Tax Residency: Ties, Sojourning and Leaving
How the CRA decides factual residency through residential ties, when the 183-day sojourning rule makes you a deemed resident, and what to do when you emigrate.
7 min read →Monthly 183 Challenge
Share your best day-tracking system or border story. Monthly prizes funded by sponsors and supporters.
Keep the tools free
Support from $5. Every contribution funds operations, new tools, contest prizes and expert reviewers.
Work with us
We hire cross-border tax writers, reviewers, developers and video creators — remote, project-based.
Quick answers
Is the 183-day rule the same in every country?
No. Many countries use 183 days, but the window differs (calendar year, fiscal year, or any rolling 12 months), some use 180 or 182 days, and several have no day test at all. Most also apply home, family and economic-interest tests.
If I stay under 183 days everywhere, am I tax-free?
Almost never. Your home country usually keeps taxing you until you break residency under its own rules, and some countries can make you resident on far fewer days through ties tests. US citizens are taxed wherever they live.
Does part of a day count as a day?
In many systems, yes — any part of a day counts. The UK generally counts days on which you are present at midnight. Always check the specific rule; our tracker lets you switch between counting methods.
Is my travel data uploaded anywhere?
No. The Day Tracker runs entirely in your browser and stores trips in local storage on your device. Export a CSV regularly as your backup.
Can you give me personal tax advice?
We publish education and tools, not advice. If your situation is complex, use the free matching form and we will connect you with an independent professional.
How current are the country summaries?
Each summary was reviewed in October 2026 and links to the official authority. Rules change — always confirm before acting.
The 183 Brief
Rule changes, new nomad visas, day-count tactics and one worked example every week. No spam — unsubscribe any time.