Koreans use it when they need a short time to think, find something, or ask someone to wait politely.
Yes. "잠시만요 (jamsiman yo)" is a standard polite expression. You can also say "잠깐만요 (jamkkanman yo)" for a slightly shorter version.
You can say "Just a little longer please" — 조금만 더요 (jo-geum-man deo-yo) or "Please wait one moment" — 잠시만 기다려주세요 (jamsiman gidaryeo-juseyo).
잠시만요 means "Wait a moment." 잠시 (jamsi) = a moment, 만 (man) = only, 요 (yo) = polite. Very common polite expression when you need time to check, find something, or ask someone to wait briefly.
1. Check something: Need time to find info.
2. Phone / shop: Ask to wait briefly.
3. Polite manner: Shows consideration.
Wait a moment. I'll check right away.
Please wait a moment.
Wait a sec, let me think. (Casual)
Please wait just a little longer.
• 잠깐만요 (jamkkanmanyo) - Just a second
• 기다려 주세요 (gidaryeo juseyo) - Please wait
• 잠시만요, 곧 올게요 (jamsimanyo, got olgeyo) - Wait, I'll be right back