How to Make an Affidavit in Japan: Sworn Certification at a Notary Office, English Sample, Apostille and the U.S. Embassy Option

Authorities, banks, courts or lawyers abroad sometimes ask for an "affidavit". An affidavit is a written statement whose author swears that its content is true, with the oath certified by a notary or other authorized person. In Japan, the author goes in person to a notary office and receives sworn certification (sensei ninsho) by swearing before the notary. If the receiving authority also requires an apostille, certifications by the Legal Affairs Bureau and the Ministry of Foreign Affairs of Japan (MOFA) follow. This page explains how to prepare an affidavit, how to write it in English, the procedure and fees at the notary office, and how it differs from notarization at the U.S. Embassy.

This page is based on the Notary Act (as amended, effective 1 October 2025), the Notary Fee Ordinance, the Japan National Notaries Association's pages on sworn certification, certification of foreign-language documents and fees, MOFA's "Application guide" and the U.S. Embassy and Consulates in Japan's "Notarial Services", as of 19 October 2026. What to write in an affidavit and which certification is needed differ by receiving authority, so always check its instructions.

In short: in Japan, sworn certification at a notary office, plus an apostille if needed

For use in the United States, notarization at the U.S. Embassy in Japan is another option, but appointments are required and only English documents are handled (see below).

What an affidavit is

An affidavit is a written statement of facts that its author (the affiant or deponent) swears is true, with the oath certified by an authorized person. It is widely used in common-law countries to prove matters for which there is no official certificate like Japan's koseki.

Japan introduced sworn certification by notaries in January 1998, allowing notaries to certify private documents signed after swearing before them. A person who swears knowing a statement is false is liable to a non-penal fine of up to JPY 100,000 (Notary Act, Article 55; formerly Article 60-5). Sworn certification therefore officially shows not only that the signature is the affiant's, but also that the affiant swore that the content is true.

How it differs from certification of signature

Notarization of private documents at a notary office includes certification of signature, which proves the signature is the signer's own, and sworn certification.

The Japan National Notaries Association notes that foreign documents titled "Affidavit" or containing words such as "swear" or "take an oath" usually require sworn certification. Check with the receiving authority whether certification of signature is enough or sworn certification is needed, and tell the notary office accurately. Even a document titled "Affidavit" may in some cases require witnessed signing before the notary rather than an oath.

Examples of when affidavits are used

• Explaining that you are an heir, or family relationships, in inheritance procedures abroad (for estate division agreements, see our guide to estate division agreements (in Japanese))
• Declaring that you are single or have never been married
• Declaring that you are the same person when your name is spelled differently in different documents
• Explaining the source of funds in citizenship or residence-by-investment applications (for example, documents for Saint Lucia citizenship (in Japanese))
• Explaining your circumstances for bank, pension or insurance procedures abroad

When an affidavit can be used and what to write differ by country and institution. If the receiving authority has provided a form, use it.

Affidavits used as proof of address by foreign nationals living abroad for property registration in Japan are generally certified by a notary in their home country or country of residence, which is a different use from this page. Please consult a judicial scrivener about registration procedures.

How to prepare an affidavit and write it in English

Content

If the receiving authority has no form, the usual order is:

1. Title: AFFIDAVIT (sometimes specifying the subject, as in "AFFIDAVIT OF SINGLE STATUS")
2. Affiant's details: name (as in the passport), date of birth, nationality, address, passport number
3. Oath wording: for example, "I, [name], being duly sworn, state as follows:"
4. Facts: numbered, one fact per item. Only facts known to the affiant, not guesses or opinions
5. Closing: for example, "I swear that the foregoing statements are true and correct."
6. Signature block: signature and date (do not sign in advance; you sign before the notary)

Example in English (affidavit of single status)

The notary's section (jurat) is replaced by the Japanese notary's certificate, so it is not included in the example. The example only illustrates the format and is not a form accepted by every receiving authority. If the receiving authority specifies wording, follow it.

Points to note when writing

• Name and date of birth must match the passport. Match the name order to the receiving authority's documents
• Dates: writing the month in words, as in "January 1, 1990", avoids confusion between day and month
• Notary section: Japanese notaries certify by attaching their own certificate to the document. If the receiving authority's form has a section for the notary's signature (such as a jurat), ask the notary office in advance how it will be handled
• Japanese translation: whether a Japanese translation must be attached to an English affidavit may differ by notary office, so ask when making the reservation

Sworn certification at the notary office: step by step

1. Check the receiving authority's instructions: whether sworn certification and an apostille are needed, and whether a form is specified
2. Prepare the affidavit: do not sign yet. Prepare two identical copies (Notary Act, Article 53(2))
3. Book an appointment at the notary office: for English documents, ask when booking whether you can send the draft in advance for review
4. The affiant attends the notary office: before the notary, stand, swear that the content is true and sign
5. Certification: one copy is kept by the notary office and the other is returned to you
6. Apostille: the Legal Affairs Bureau to which the notary belongs certifies the notary's seal, and MOFA issues the apostille

ID

According to the Japan National Notaries Association, individuals bring one of the following (seal registration certificates must be issued within three months):

• Seal registration certificate and registered seal
• Driver's license and a personal seal
• My Number Card and a personal seal
• Passport, residence card, etc. and a personal seal

Foreign nationals living in Japan can use their residence card or passport with a personal seal. Spell your name in the affidavit as in the roman letters of your passport. If a company representative swears and signs with their title, the representative swears personally, and the certificate of the representative's capacity (such as a certificate of registered matters), the company's representative seal and its seal certificate are needed. Required documents for sworn certification may differ by notary office, so check when booking.

If the affiant is not in Japan

Sworn certification cannot be done through an agent, so to prepare the affidavit at a Japanese notary office the affiant must come to Japan. The law also provides for swearing by video and audio communication if the affiant requests it and the notary considers it appropriate (Notary Act, Article 53(4)). However, you need to check with the notary office whether this is available for affidavits for use abroad or from overseas. If you live abroad, it may be quicker to use a notary in your country of residence, or the embassy or consulate of the receiving country there.

Adding an apostille

An affidavit is a private document, so it cannot be submitted to MOFA directly. After notarization, it is certified in the following order.

At notary offices in Hokkaido (Sapporo Legal Affairs Bureau area), Miyagi, Tokyo, Kanagawa, Shizuoka, Aichi, Osaka and Fukuoka, the notarization, the Legal Affairs Bureau's certification and MOFA's apostille are obtained at once (one-stop service). For countries that are not parties to the Hague Convention, a certificate of official seal from MOFA and consular legalization by that country's embassy or consulate are needed instead of an apostille (see Apostille vs. consular legalization).

How it differs from notarization at the U.S. Embassy

Affidavits for the United States can also be prepared through the notarial services of the U.S. Embassy in Tokyo and the consulates. The differences from a Japanese notary office are as follows (based on the embassy's guidance as of October 2026).

The embassy states that it does not certify copies of documents such as bank statements or transcripts, does not provide medallion signature guarantees, and does not handle affidavits for Japanese corporate registration. It also stopped handling sworn statements of legal capacity to marry for marriages in Japan on 1 September 2025.

The United States is a party to the Hague Convention. The U.S. Department of State advises that people in Convention countries can prepare documents with a local notary's certification and an apostille. If you cannot get an embassy appointment, ask the receiving authority whether an affidavit with sworn certification at a Japanese notary office and an apostille is acceptable.

FAQ

Can I write the affidavit myself?

Yes. An affidavit is a private document prepared by the affiant, and no qualification is required to write it. If you write it in English, check that it covers what the receiving authority requires and that the spelling matches your passport and other documents.

Can a family member swear at the notary office on my behalf?

No. Sworn certification is a procedure in which the affiant swears before the notary, and the law prohibits doing it through an agent (Notary Act, Article 53(3)).

Does an affidavit expire?

There is no legal expiry date. However, the receiving authority may set a time limit, such as "within three months of execution", so prepare it to match your submission date.

Can I write it in Japanese and attach an English translation?

Yes. You can receive sworn certification for a Japanese affidavit and attach the English translation with a translator's declaration that is itself notarized (certification of signature), or write the English and Japanese side by side. Check with the receiving authority which form it accepts.

Our service

Our office (Taiga Sato, Certified Administrative Scrivener) can help with affidavits as follows. Because the oath is sworn by the affiant before the notary, the affiant must attend the notary office in person.

• Drafting English affidavits in line with the receiving authority's instructions
• Translating affidavits written in Japanese and attached documents
• Booking the notary office and preparing the draft for review with the notary in advance
• Obtaining the Legal Affairs Bureau's certification and MOFA's apostille after sworn certification
• Shipping abroad

Drafting affidavits for lawsuits or other disputes is the work of attorneys, so we do not draft them. In that case, we help with translation, preparing for the notary office and obtaining the apostille, based on the draft prepared by the attorney in charge (including attorneys abroad).

Actual costs such as the notary fee (JPY 17,000 per English sworn certification) and postage are charged separately. MOFA and the Legal Affairs Bureau charge no fees. We obtain certifications in Japan on your behalf; we do not verify or guarantee the truth of the affidavit's content, nor that the receiving authority will accept the documents.

For the process for private documents in general, see our guide to private documents; for the overall process, What is an apostille?; and for fees, Fees.

Free quote and inquiry form / Phone: +81-3-6303-1664 (weekdays 9:00–20:00 Japan time; weekends and holidays by appointment)

References (official sources)

• Notary Act (elaws, in Japanese)
• Japan National Notaries Association, "Sworn certification" (in Japanese)
• Japan National Notaries Association, "Certification of foreign-language documents" (in Japanese)
• Japan National Notaries Association, "Certification of private documents" (in Japanese)
• Japan National Notaries Association, "Required documents" (in Japanese)
• Japan National Notaries Association, "Fees" (in Japanese)
• Ministry of Foreign Affairs, "Application guide 1: Documents that can be certified" (in Japanese)
• Ministry of Foreign Affairs, "Application guide 2: Certification of private documents" (in Japanese)
• Tokyo Legal Affairs Bureau, "Certification of notaries' seals" (in Japanese)
• U.S. Embassy and Consulates in Japan, "Notarial Services"
• U.S. Department of State, "Notarial and Authentication Services of U.S. Consular Officers Abroad"
• Ministry of Justice, proof of address for foreign nationals living abroad (in Japanese)