A few polite expressions for asking someone to repeat what they said:
- US not UK: Excuse me?
- Sorry, could you repeat that, please?
- Sorry, can you say that again, please?
- Sorry, I didn’t (quite) catch that.
- Sorry, can you speak up a bit, please? (On the telephone if the phone line is bad)
- Sorry, can you speak a bit more slowly, please? (If there’s a language problem)