When a Japanese and a foreigner get married internationally, in principle, the couple will have separate surnames.Japanese law permits the couple to take the surname of the foreign partner while retaining their Japanese nationality. In this case, the procedure is to change the surname. There are also ways for the foreign partner to take a Japanese surname or a compound surname(複合姓), and the procedures are explained below.
There are three options for your surname when you get married internationally.
When you get married internationally, there are three options: “separate surname for married couples”, “take the surname of your partner”, or “take a compound surname”.
International Marriage and the Principle of Family Name and Surname
In Japan, there is a “family register(戸籍)”, so when two Japanese people marry, they create a single family register. Since there is only one surname and family name per “family register”, Japanese couples will have the same surname.
Only Japanese nationals can have a family register. Foreigners do not have a family register, and the same is true when married to a Japanese national.
Therefore, when a Japanese and a foreigner get married, the surname of the Japanese will not be changed unless special procedures are taken, and the couple will have separate surnames. However, it is possible to take the surname of the foreigner by completing the necessary procedures.
The Three Options for Last Name (Surname)
As explained in the previous section, foreigners do not have a “family register”, so when a Japanese and a foreigner marry, they cannot have the same surname without going through procedures. However, they can “take the other person’s surname” or “take a combined surname” in addition to the “separate surname” by going through procedures.
・take the other person’s surname
・take a compound surname
Taking the surname of the foreign spouse
Japanese nationals can take the surname (family name) of their foreign partner while maintaining their Japanese nationality.
What condition?
In Japan, a Japanese national married to a foreigner may take the family name of the foreign partner. In this case, the Japanese national will take the surname (family name) of the partner while retaining his/her Japanese nationality. However, they cannot take a surname other than that of the foreign partner (meaning that they cannot take the opportunity of marriage to change the surname to that of an unrelated person) In this case, you will be changing your Japanese family register, meaning that your real name will change. However, there are rules regarding the notation of the name in Japan, and it is necessary to change the letters of the alphabet to katakana, for example.
What procedures are required?
If you wish to take the surname of your foreign partner, you must submit a “Notification of Change of Family Name((氏（姓）の変更届)” to the municipal office within 6 months of the marriage. If the procedure is to be taken after 6 months, a petition for change of surname must be filed at the family court. In this case, the petition should be filed with the family court that has jurisdiction over the area where the applicant resides.
When taking the surname of the Japanese spouse
There are two ways for a foreigner to take the surname of his/her Japanese partner, depending on the laws of his/her home country, either by changing it (changing the real name in the home country) or by registering a common name(通称名).
What condition?
If a foreigner wishes to take the surname of his/her Japanese partner, he/she must first check the laws of his/her home country. In principle, when a Japanese person marries a foreigner, the couple will have separate surnames, but this may change if the laws of the home country require that the surname be changed. In this case, it means that the foreign partner’s real name will be changed.
If the law of your home country does not change your surname upon international marriage, you will register a “common name” that can be used only in Japan if you take the surname of your Japanese partner.
What procedures are required?
If your surname changes in your home country (your real name changes), you must go through the procedures in your home country. If you wish to register a common name, you must apply for it at the Japanese municipal office.
In the case of a surname change in the home country
If the surname changes according to the rules of the foreign partner’s home country, the procedure is to be taken in the home country. The procedure is carried out in accordance with the laws of each country. After that, the spouse’s name in the family register of the Japanese partner will be changed. By submitting a “Request for Change of Spouse’s Last Nam(e配偶者の姓の変更の申出)” with documents showing that the real name has changed after the marriage, the spouse’s name in the family register of the Japanese can be changed.
When the real name is changed, it is necessary not only to go through the family register procedures, but also to change the surname on official documents, etc. that are linked to the change of the real name. For example, you will have to change your residence card, passport, driver’s license, etc. without omission.
How to register a common name
You can register your common name at the municipal office where you have your resident registration. You can register a common name by submitting a document titled “Application for Registration of Common Name(通称記載申出書)”. The common name will appear on the resident registration card, but will not be included in the family register or on the residence card.
In case of taking a compound surname
It is possible to take both the surname of the foreign spouse and the existing surname. Such a situation is called a ” compound surname”.
What condition?
With a compound surname, you can take both your surname and your partner’s surname.
However, the Japanese name (the name that can be registered in the family register) is the first name and the last name, and the middle name cannot be added. You will have to put your middle name in either the “first name” or the “last name”. Therefore, a petition for change must be filed at the family court in the following form.
（Last name）ロッシ田中 （First name）良子
（Last name）田中ロッシ （First name）良子
・Change of last name and first name
（Last name）ロッシ （First name）田中良子
This procedure will change the name that appears in the family register, and changing the family register means changing the real name.
What procedures are required?
This procedure is done by filing a petition with the family court that has jurisdiction over the area of residence. A change of surname or name will be approved when there are justifiable or unavoidable reasons, so be sure to prepare your reasons well before filing the petition. Along with the grounds for the petition, it is advisable to present evidence of the use of a compound surname in the home country or mail, etc.
Conclusion
These are the three options for a surname in the case of an international marriage.
If you do not follow any procedures, you will basically have separate surnames for married couples, but Japan allows you to take the surname of your married partner. If you follow the procedures, you can change your name in the family register. Foreign partners are also allowed to take a Japanese surname in Japan by registering a common name, although this depends on the laws of their home country. There is also the option of a compound surname, although this is a procedure that must be completed at the family court.
