it's nothing; don't mention it; no thanks necessary
A polite phrase used to decline thanks or downplay one's own help, similar to 'you're welcome' or 'think nothing of it'. The more polite form is お礼には及びません.
See also: お礼には及びません (おれいにはおよびません)
"Thanks for helping me." "It's nothing."
お礼には及びません。当然のことをしたまでです。
No thanks are necessary. I only did what was natural.