Translation guide
The English word 'unauthorised' (or 'unauthorized') describes actions, access, or items that lack official permission. In Japanese, this concept is expressed through specific adjectives, verbs, and set phrases depending on context, such as official documents, computer access, or general permission.
To describe an action, entry, or item that is not officially permitted, often in formal or legal contexts.
A prefix meaning 'without permission' or 'unauthorised'. Commonly used in compound nouns like 無断使用 (unauthorised use) or 無断転載 (unauthorised reproduction). Very natural for formal warnings.
無断駐車は禁止されています。
Unauthorised parking is prohibited.
この資料の無断転載を禁じます。
Unauthorised reproduction of this material is forbidden.
A phrase meaning 'not permitted' or 'unauthorised'. It is a direct and clear way to state that something lacks authorization. Suitable for both spoken and written contexts.
許可されていないアクセスが検出されました。
Unauthorised access was detected.
このエリアは許可されていない人は入れません。
People who are not authorised cannot enter this area.
Means 'illegal', 'unauthorised', or 'fraudulent'. Often used in contexts like 不正アクセス (unauthorised access) or 不正使用 (unauthorised use). Implies wrongdoing or violation of rules.
不正アクセスは犯罪です。
Unauthorised access is a crime.
不正な手段で情報を入手した。
They obtained information through unauthorised means.
A more formal term meaning 'not authorised' or 'not approved', often used in legal or administrative contexts. Less common in everyday speech.
認可されていない医薬品の販売は違法です。
Selling unauthorised pharmaceuticals is illegal.
Specifically referring to accessing a computer system, network, or data without permission.
The standard term for 'unauthorised access' in IT and legal contexts. Widely understood and used in news and warnings.
不正アクセス禁止法に違反する行為です。
This act violates the Unauthorised Access Prohibition Law.
サーバーへの不正アクセスが相次いでいる。
There have been a series of unauthorised accesses to the server.
A more literal translation, 'access that is not permitted'. Used in technical documentation or formal explanations.
許可されていないアクセスを検知した場合、直ちに報告してください。
If you detect unauthorised access, report it immediately.
Describing the use, copying, or distribution of copyrighted material, trademarks, or confidential information without permission.
Means 'unauthorised use'. Common in legal notices and terms of service.
当社のロゴの無断使用は固くお断りします。
Unauthorised use of our company logo is strictly prohibited.
Specifically means 'unauthorised reproduction' or 'reprinting without permission'. Very common on websites and in publications.
当サイトの内容の無断転載を禁止します。
Unauthorised reproduction of the content of this site is prohibited.
Means 'illegal copy' or 'unauthorised copy'. Often used for software or digital media.
Referring to a person who is not allowed to enter a place or access information.
A common sign meaning 'Authorised Personnel Only' or 'No Entry for Unauthorised Persons'. Literally 'Entry prohibited except for concerned persons'.
このドアには「関係者以外立入禁止」と書いてある。
This door says 'Authorised Personnel Only'.
A straightforward phrase meaning 'a person without permission'. Used in spoken warnings or instructions.
許可のない人はこのフロアに入らないでください。
Unauthorised persons, please do not enter this floor.
無断 (むだん) simply means 'without permission' and is neutral about legality. 不正 (ふせい) implies illegality or wrongdoing. Use 無断 for general lack of permission (e.g., 無断欠勤 - unauthorised absence from work) and 不正 for criminal or rule-breaking acts (e.g., 不正アクセス - unauthorised access).
Avoid directly translating 'unauthorised' as 非公認 (ひこうにん) or 未承認 (みしょうにん) in most contexts. 非公認 often means 'unofficial' (not officially recognized), and 未承認 means 'unapproved' (not yet approved). They do not convey the active lack of permission implied by 'unauthorised'.
不正コピーされたソフトウェアはサポート対象外です。
Unauthorised copies of the software are not supported.