Translation guide
A company that provides wireless voice and data services for mobile phones. In Japanese, this is typically expressed with specific terms for the carrier or the industry.
Referring to a company that provides mobile phone services.
Formal term for a mobile phone carrier. Commonly used in business and official contexts.
The three major mobile network operators dominate the market in Japan.
Common loanword for a mobile carrier. Widely used in everyday conversation and media.
どのキャリアを使っていますか？
Which mobile network operator do you use?
More technical term, often abbreviated as MNO. Used in regulatory or industry contexts.
移動体通信事業者は周波数帯の割り当てを受ける。
Mobile network operators receive frequency band allocations.
General term for a telecommunications carrier, which can include mobile operators. Context usually clarifies it's mobile.
通信事業者が新しい料金プランを発表した。
The mobile network operator announced a new pricing plan.
Referring to a particular mobile network operator by name.
In Japanese, just use the company name (e.g., NTTドコモ, KDDI, ソフトバンク) without adding 'mobile network operator' unless necessary for clarity.
NTTドコモは日本最大の携帯電話事業者です。
NTT Docomo is Japan's largest mobile network operator.
Referring to a company that provides mobile services using another operator's network.
Formal term for MVNO. Used in official and technical contexts.
仮想移動体通信事業者は自社のネットワークを持たない。
Mobile virtual network operators do not own their own network infrastructure.
The English abbreviation is commonly used in Japanese, pronounced エムブイエヌオー.
格安SIMはMVNOが提供している。
Budget SIM cards are provided by MVNOs.
Commonly used to refer to MVNOs that offer low-cost SIM cards. More consumer-oriented.
格安SIM事業者に乗り換える人が増えている。
More people are switching to budget mobile network operators.
The loanword キャリア is very common and understood by all. It's safe to use in most situations, from casual to semi-formal. For very formal writing, prefer 携帯電話事業者.
In Japanese, the distinction between facilities-based operators (MNO) and virtual operators (MVNO) is often made with 移動体通信事業者 (MNO) and 仮想移動体通信事業者 (MVNO). In consumer contexts, people often just say キャリア for major operators and 格安SIM for MVNOs.