From Longman Dictionary of Contemporary Englishno thanksno thanks informalNOused to say politely that you do not want something ‘How about some cake?’ ‘Oh, no thanks, I’m on a diet.’ → thanks
Examples from the Corpus
no thanks• Thanks, but - no thanks!• Carrie said we could do another screen but I said no thanks.• He offers me a free go too but I just stick my nose in the air and say no thanks.• I threw the last one's sketches across his office and told him: shoddy, unexciting, no thanks.• No great compliments, no thanks.• I offer to buy him a fibreglass canoe but he says no thanks, he already has one.• She didn't think that there was anything broken ... but no thanks to Johnny, she thought bitterly. 