Electronic Filing and Digital Signature — Overview

Company registration (登記, through the Legal Affairs Bureau) and tax registration are separate, independent procedures. Filings can be submitted online via a card reader, in person, or by mail. A digital signature is applied via the My Number Card, the same tool needed for e-Tax/eLTAX. Several government systems (e-Tax, e-Gov, gBizID) each have their own technical quirks and known issues, such as mismatches between a name in Latin script and in katakana. Details of each system follow below. Company registration (登記, through the Legal Affairs Bureau / Homukyoku) and tax registration are separate procedures, and one does not substitute for the other. Filing methods are: online via a card reader, in person at the Legal Affairs Bureau, or by mail if no card reader is available. Card readers are sold on Amazon from about 2,000 yen (a Sony model was mentioned); some work immediately, others require installing extra, specific software (problems were noted on macOS). The Ministry of Justice's official registration software only runs from 8:30 to 21:30 (the server is shut off overnight) and requires patience — registration is often outsourced to a Japanese-speaking person just for speed. A digital signature on the articles can be applied via the My Number Card (マイナンバーカード) using JPKI tools (or OpenSC through MacPorts on macOS) and a card reader; setup can take a while — one participant called it a "two-day driver quest." On Windows, an instruction guide at contents.shinonomekazan.com/tips/pdf-sign-by-mynumber-card.html (using the OpenSC program) was used. Signing can be done remotely from home, though some participants preferred doing it in person with the notary. The My Number Card is also used for electronic tax forms (e-Tax/eLTAX), which requires a smart-card reader (ISO/IEC 7816) and the JPKI利用者ソフト software; some ThinkPad T-series laptops have an optional built-in reader. A smartphone's NFC can also read the card for e-Tax, but it does not always work for eLTAX. For registering a GK without freee — for example if freee refuses to file because of a katakana name — there is a self-filing guide through the Ministry of Justice site at yutoryman2019.com/goudougaisya/houjin-shinsei. Documents prepared in freee can be taken and filed directly with the Ministry of Justice, bypassing freee's automated submission. e-Tax comes in three easily confused versions: a full, complex system for all operations ("terrible" by user reports), a simplified version for individual income-tax returns, and an even simpler mobile version. e-Tax calculates NTA taxes (income tax, etc.) but NOT local taxes (resident tax) or social insurance — those must be calculated separately. e-Gov is a unified filing system, including for pension/insurance filings, implemented as a browser wrapper; it is the only one of these systems requiring two-factor authentication (Google Authenticator, etc.). A technical wrinkle: the character "ー" (katakana dash) cannot be used in some fields (the error is not immediately obvious); the character "―" visually converts to "ー" but is handled incorrectly on submission — the list of forbidden characters is at shinsei.e-gov.go.jp/contents/help/notes/letters.html. When binding a digital certificate (My Number), the name and date of birth must be entered EXACTLY as on the card, including case. gBizID is the unified authentication system for business-related government services; freee also automatically files some documents through it. A frequent technical problem is a mismatch between the name on My Number (Latin/romaji) and the representative's name in the company registration (katakana), which triggers "Name mismatch" rejections. Workarounds include filing on paper, adding a katakana entry in the 備考欄 (remarks field) of the residence record, or obtaining a 通称名 (alias name). From July 2026, gBizID accounts will start expiring after 2 years and 3 months (gbiz-id.go.jp/top/account_expiry/account_expiry.html); online registration via My Number will not work for renewal — only paper mail will. Registering a 通称名 (tsushomei, an alternate name, e.g. in katakana) helps resolve name-mismatch problems across documents: a katakana tsusho is registered relatively easily, while a kanji tsusho (an "anime name") requires solid proof of use (work certificates, utility bills, letters from friends over six months), and some municipalities refuse it more often; a tsushomei can only be registered once and cannot be changed. A separate procedure to officially change the spelling of one's name (on the 在留カード) from katakana to Latin script costs around 35,000 yen. Japanese tax PDF forms are more comfortably filled out on Windows with the free Adobe Acrobat Reader and correctly installed Japanese fonts — on Linux and in-browser, font size often shifts or the program crashes. In Adobe Reader text can be typed anywhere on the PDF, not just in the form fields. Source: https://contents.shinonomekazan.com/tips/pdf-sign-by-mynumber-card.html — Guide to signing a PDF via the My Number Card on Windows with the OpenSC program. Source: https://yutoryman2019.com/goudougaisya/houjin-shinsei — Guide to filing a GK registration directly with the Ministry of Justice without using freee. Source: https://shinsei.e-gov.go.jp/contents/help/notes/letters.html — List of forbidden characters for e-Gov form fields. Source: https://gbiz-id.go.jp/top/account_expiry/account_expiry.html — Official gBizID information on the 2-years-3-months account expiry rule, effective July 2026.