A Japanese Phrase for Asking someone to repeat something on the phone: "もう一度言っていただけますか？"

"もう一度言っていただけますか？" means "Could you say that again?" and it's the basic Japanese expression used for asking someone to repeat something on the phone. It's very handy for phone calls and online communication. To answer, you can say something like "はい、もう少しゆっくり言います。" (Yes, I'll say it a bit more slowly). You can keep the conversation going by reacting with something like "ありがとうございます、助かります。" (Thank you, that helps).