We use this expression to express that there’s no need to thank someone.
You can use this phrase in ………… language.
Spoken
Informal
Example 1
A: I’m so grateful to you for giving me that recommendation to the job! If it wasn’t for you, I’d be still unemployed.
B: That’s all right, don’t mention it.
Example 2
A:Thank you for helping out with the kids.
B:Don’t mention it, it’s no big deal.