Introduction
In international taxation, the number "183 days" frequently appears in the context of determining residency and exemptions for short-term visitors. However, even with the same 183 days, the purpose of the 183 days and how to count the entry and exit dates differ according to each country's domestic tax laws and tax treaties. It is particularly important for individuals traveling between Japan, China, and the United States to accurately understand these differences.
First conclusion - How to count entry and exit dates
| System | Entry date | Exit date | Basic concept |
|---|---|---|---|
| Residency determination under Japanese domestic law | ― | ― | There is no general 183-day standard |
| 183-day determination under Chinese domestic law | Generally not included | Generally not included | Only days spent in China for 24 hours are counted as one day. |
| Substantial Presence Test under U.S. domestic law. | Generally included. | Generally included. | If present in the U.S. for any part of the day, it is counted as one day. |
| General 183-day determination under tax treaties. | Generally included. | Generally included. | Under the physical presence method, any part of the day is counted as one day. |
Thus, even though the same expression "183 days" is used, the method of counting those days is not necessarily the same. In particular, under Chinese domestic law, the 24-hour rule is adopted, so the usual entry and exit dates are not included in the residency days.
Chinese domestic law - Entry and exit dates are usually not counted.
Under Chinese individual income tax law, for individuals without a residence in China, whether they have resided in China for more than 183 days in a calendar year is an important factor for tax purposes.
Regarding the number of days of stay, in China, it is calculated as one day if the individual has stayed in China for 24 hours on that day, and days of stay of less than 24 hours are not included in the residency days. Therefore, the usual entry date is spent outside the country before entry, and the exit date is also spent outside the country after exit, so neither qualifies as a day spent in China for 24 hours and is generally not included in the residency days.
For example, if a person enters China on January 1, 2026, and exits China on July 2, 2026, there are 183 days on the calendar from the entry date to the exit date, but under Chinese domestic law, the residency days are calculated as 181 days from January 2 to July 1.
Therefore, in the determination of 183 days for Chinese individual income tax, simply calculating the number of days from the entry date to the exit date on the passport may not yield accurate results.
U.S. domestic law - Both entry and exit dates are generally counted.
In the U.S., one of the criteria for determining whether a foreigner qualifies as a U.S. tax resident is the Substantial Presence Test (SPT).
Under the SPT, it is generally assumed that the individual has stayed in the U.S. for at least 31 days in the current year, and the total is determined by adding 100% of the days stayed in the U.S. in the current year, one-third of the days stayed in the U.S. in the previous year, and one-sixth of the days stayed in the U.S. in the year before that, and checking if the total is 183 days or more.
In this calculation, it is generally counted as one day if the individual is physically present in the U.S. for any part of the day. Therefore, usually, the entry date counts as one day, and the exit date counts as one day. However, not all days spent in the U.S. are necessarily included in the SPT days. For example, days spent passing through the U.S. for less than 24 hours while traveling between two locations abroad, periods that qualify as "exempt individuals" under U.S. tax law for certain students, teachers, trainees, etc., and stays for certain medical reasons may be excluded from the day count.
Additionally, even if the SPT is met, if the actual number of days stayed in the U.S. is less than 183 days, and there is a tax home in a foreign country with a closer connection to that foreign country than to the U.S., certain conditions may allow for treatment as a non-resident alien under the Closer Connection Exception.
Therefore, the "183 days" in the U.S. is not a system that simply counts the number of days stayed in the current year, but rather a unique system that weighs the number of days stayed over multiple years.
Japanese domestic law - There is no general "183-day rule."
Domestic Law in Japan - There is no general "183-day rule"
Under Japan's income tax law, individuals who have a residence in the country or individuals who have continuously had a residence for more than one year are generally considered residents.
Here, "residence" means the primary place of living and is not determined solely by the number of days spent in Japan. Whether a person has their primary place of living in Japan is determined by comprehensively considering factors such as residence, occupation, family location, assets, and other objective facts.
Therefore, there is no general 183-day rule in Japan's domestic law stating that "if you stay in Japan for more than 183 days in a year, you become a resident, and if less than 183 days, you become a non-resident."
Moreover, when determining whether one has a "continuously maintained residence for more than one year," a period calculation is necessary, but this also differs from the 183-day standard. In this regard, Japan's resident determination fundamentally differs from the systems centered on the number of days stayed in China or the United States.
183 days under tax treaties - both the entry and exit dates are generally counted.
On the other hand, the "183 days" standard is widely used in tax treaties for short-term stay exemptions for employment income.
In a typical tax treaty, a mechanism is established to exempt taxation in the host country for certain employment income if the stay in the host country does not exceed 183 days, the salary is paid by an employer who is not a resident of the host country, and the salary is not borne by a permanent establishment located in the host country.
In calculating these 183 days, the physical presence method is generally adopted, which is based on the number of days physically present in that country. Under this method, if a person is present in that country for even part of a day, it is counted as a full day, so typically, both the entry and exit dates are included in the number of days stayed.
For example, if a person enters on January 1, 2026, and exits on July 2, 2026, the number of days stayed under the tax treaty would be calculated as 183 days from January 1 to July 2.
As a result, even with the exact same stay period, it may be 181 days under Chinese domestic law and 183 days under the tax treaty. Therefore, the same number of days cannot be used directly for determining residency under domestic law and for short-term stay exemptions under tax treaties.
The period for which the "183 days" is counted also varies by treaty.
It is also important to note that the period for counting the 183 days itself varies by tax treaty.
Some treaties use a calendar year, meaning the number of days stayed from January 1 to December 31 as the basis, while other treaties may use a specific tax year or any 12-month period that begins or ends in that tax year.
This difference is very important in practice. For example, if a person works continuously from July of one year to June of the following year, even if they are below 183 days in each calendar year, they may exceed 183 days under a treaty that assesses based on "any 12-month period."
Therefore, in practice, it is necessary to not just look at whether they have "exceeded 183 days," but to confirm, which law or tax treaty the 183 days are based on, what the 183 days are for, whether to include entry and exit dates, and whether to use a calendar year, tax year, or any 12-month period as the basis. It is necessary to determine the 183 days under domestic law and tax treaties separately.
The 183 days under domestic law and tax treaties require separate assesment
What is particularly important to note in practice is that the number of days for determining residency under domestic law and the number of days for tax exemption for short-term stay under tax treaties serve different purposes.
For example, even if certain non-resident treatment applies under Chinese domestic law because it is less than 183 days, the same stay period may be counted as 183 days under the tax treaty, potentially failing to meet the requirements for short-term stay exemptions.
Conversely, even if one is already determined to be a resident under domestic law, if they become a resident under the domestic laws of both countries in relation to another country, a separate determination may be required under the resident clause of the tax treaty, known as the tie-breaker rule.
Therefore, it is not appropriate to simply judge that "no tax applies because it is less than 183 days" or "one becomes a resident because it exceeds 183 days."
Summary
In international taxation, the term "183-day rule" is frequently used, but there is no single 183-day rule that is universally applicable.
Under Chinese domestic law, only the days spent in China for 24 hours are counted as one day, so the usual entry and exit dates are not included in the number of days of residence. In contrast, under the U.S. Substantial Presence Test, if one is physically present in the U.S. for any part of the day, it is treated as one day, so both entry and exit dates are typically counted. Japanese domestic law does not have a general 183-day resident standard; instead, residency determination is based on one's address or a residence of more than one year.
Additionally, regarding the 183 days for short-term stay exemptions under tax treaties, the physical presence method is generally used, and both entry and exit dates are typically counted. Furthermore, the period for counting the 183 days can differ by treaty, including calendar year, tax year, or any 12-month period.
For employees who are frequently assigned overseas, work in multiple countries, or have many short-term business trips, it is important to manage not with a single "stay days table," but to separate the days for residency determination under each country's domestic law and the days for short-term stay exemption determination under tax treaties. This separation is practically important.* This article provides an overview of general systems. When determining actual residency and applying tax treaties, it is necessary to individually confirm the specific provisions of the applicable countries, target years, purpose of stay, residency status, employment relationships, payment and burden relationships of salaries, and applicable tax treaties.
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