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Certified Japanese Name Change Document Translation

Certified translation of the documents that record a change of name in Japan, including the marginal annotations and registry endorsements that carry the legal effect and that a reader unfamiliar with the system will otherwise skip.

The koseki, and the family court

A Japanese name lives in the koseki (戸籍), the family register, and changing it requires permission of the family court — a surname needs yamu o enai jiyū, an unavoidable reason, and a given name needs a legitimate one. Neither is granted casually.

Once permitted, the change is entered in the koseki and the register shows it. The court permission and the koseki entry are two documents, and a complete packet usually needs both.

Koseki tōhon, and the versions that hide history

A koseki tōhon shows the whole register and a koseki shōhon only one person. More importantly, Japan computerised the registers, and the current register may not carry entries that were in the previous one — the kaisei genkoseki (改製原戸籍), the pre-computerisation original, holds them.

A change of name from before computerisation may therefore be invisible on the current tōhon. If your register shows nothing, ask for the kaisei genkoseki and, for a register you have left, the joseki.

Marriage requires one surname

Japan requires spouses to share a single surname — the Civil Code permits no other option, and Japan is alone among major economies in that. In practice the wife takes the husband's name in the overwhelming majority of marriages.

So a Japanese woman's surname change on marriage is a legal change recorded in the koseki, not a social convention, and the document trail is the marriage entry rather than a name-change order. A separately used maiden name (tsūshō) has no registry status.

Kanji readings, and Hepburn

Japanese names are written in kanji whose reading is not determined by the characters — 東海林 can be Shōji or Tōkairin — so the koseki's furigana, where present, is what establishes the reading. We reproduce the characters and give the reading the document supports.

Passports use Hepburn romanisation and drop long-vowel marks, so Satō becomes Sato and Ōno becomes Ono, which merges names that are distinct in Japanese. We note that rather than letting it pass. See our Japanese page.

Ordering, and what the certification covers

Upload the document, choose certified translation at $24.95 per page of up to 250 words, and it comes back typically within 24 hours as a PDF formatted to mirror the original, with a signed certificate of translation accuracy on letterhead. Marginal annotations are translated in place, in the margin, so the reader can see that the change was recorded against the original entry rather than written into a fresh document. See how we translate and certified versus standard.

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