N4 · Phrase guide
結構です
けっこうです
No thank you / I'm fine
Implies you are satisfied already. Softer than blunt いらないです in many service contexts.
At meals, refusing more rice with 結構です is standard. Smile and hand gesture (palms forward) help.
お代わりは結構です。
No more refills, thank you.
Restaurant
今日は結構です。
I'm good for today.
Declining a drink offer