I wouldn't know ((anything) about that)

I wouldn't know ((anything) about that)

I have no knowledge or familiarity with what you are asking or discussing. Can be used glibly or sarcastically. A: "I absolutely love Barbados. It's one of the most beautiful places in the world!" B: "Hmm, I wouldn't know. I've never been able to afford a trip there." A: "I was wondering if you could help me. I need to fill out a form to have the deadline for my application extended." B: "I'm sorry, I wouldn't know anything about that." A: "Do you know how these drugs got here?" B: "No sir, officer, I wouldn't know about that."
See also: know
Farlex Dictionary of Idioms.

(I) wouldn't know.

There is no way that I would know the answer to that question. John: When will the flight from Miami get in? Jane: Sorry, I wouldn't know. Bob: Are there many fish in the Amazon River? Mary: Gee, I wouldn't know.
See also: know
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • wouldn't know
  • (Is) that everything?
  • Where have you been all my life?
  • this just in
  • (one) will be lucky
  • (one) would be lucky
  • (I) would if I could
  • Who would have thought it?
  • (one) should be so lucky
  • (well,) I never!