Translation guide
A phone service that alerts you to an incoming call while you are already on another call. In Japanese, it is commonly referred to by the English loanword, and there are set phrases for using the feature.
コールウェイティング
call waiting (service)
Referring to the call waiting feature on a phone.
The standard term, borrowed from English. Used in phone settings and by service providers.
コールウェイティングを設定する。
Set up call waiting.
A common brand-originated term (from NTT) that is widely understood, especially among older generations. Still used in casual conversation.
キャッチホンが鳴った。
Call waiting beeped.
Describing the action of answering a call waiting call or switching between calls.
A natural way to say 'answer another call while on the phone'. Literally 'during a call, pick up another phone'.
通話中に別の電話に出てもいいですか。
Is it okay if I answer another call while we're talking?
Specifically 'answer the call waiting'. Uses the brand term キャッチホン.
ちょっと待って、キャッチホンに出るね。
Hold on, I'll answer the call waiting.
Means 'switch calls'. Used when toggling between the current call and the incoming call.
通話中に電話を切り替える方法を教えてください。
Please tell me how to switch calls during a conversation.
Telling the person you are currently talking to that you have another call coming in.
Polite and common way to say 'Sorry, I have another call coming in.'
すみません、別の電話が入っています。少々お待ちいただけますか。
Sorry, I have another call coming in. Could you hold for a moment?
Casual way using キャッチホン. 'Call waiting is ringing, so please wait a moment.'
あ、キャッチホンが鳴ってるので、ちょっと待ってください。
Oh, call waiting is beeping, please hold on a sec.
キャッチホン is a trademark of NTT but has become a genericized term in everyday speech. コールウェイティング is the more formal, technical term used in manuals and by mobile carriers. Both are understood.