Guide
The 183-day rule and US residence
How the substantial presence test actually counts days, and why it catches people who spent well under 183 days in the US this year.
The count is weighted, and it reaches back two years.
The substantial presence test is widely described as a 183-day rule, which is misleading. It weights days across three years, so you can become resident having spent nowhere near 183 days in the US this year.
Becoming resident means being taxed on worldwide income, so the count is worth tracking rather than estimating.
At a glance
- Current year
- All days counted
- Prior year
- One third of days counted
- Year before
- One sixth of days counted
- Threshold
- 183 on the weighted total, with at least 31 days in the current year
- Exceptions
- The closer connection exception, treaty tie-breaker, and exempt individuals
In detail
01
How the weighting works
120 days a year for three years reaches 180 on the weighted count — just under. A slightly heavier travel year tips you over without any single year approaching 183.
02
The closer connection exception
Available where you were present under 183 days in the current year and can show a closer connection to another country. It is claimed on a form, not assumed.
03
Exempt individuals
Certain students, teachers and diplomats do not count days at all for a period. This is a genuine exception rather than a general escape.
04
If you cross the line
You become taxable on worldwide income from the residency start date, with FBAR and FATCA reporting attaching too. The arrival year has planning options the following years do not.
How the substantial presence test actually counts days, and why it catches people who spent well under 183 days in the US this year.
Frequently asked
Does a partial day count?
Generally any day you are physically present counts as a full day, with limited exceptions such as transit in some circumstances.
I travel to the US often for work. Should I be tracking this?
Yes, and contemporaneously. Frequent business travellers are exactly who this catches, and reconstructing years of travel later is unpleasant.
Does a visa protect me?
Most visa categories are irrelevant to the day count. The exempt individual rules are narrow and do not cover ordinary business travel.
This guide is general information, not advice for your circumstances. Cross-border tax turns on detail, and the right answer for someone with a similar situation may not be the right answer for you. Talk to us before acting on anything here.
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