  Precision flavor experiments can look for the QCD axion complementarily to
usual searches with axion helio- and haloscopes, allowing to test PQ breaking
scales as high as $10^{12} \, {\rm GeV}$. Such searches are sensitive to
flavor-violating axion couplings, which are generic and potentially sizable
whenever SM fermions carry flavor non-universal PQ charges. A particularly
predictive scenario is obtained when PQ is identified with the simplest FN
flavor symmetry, so that all flavor-violating axion couplings are related to
Yukawa hierarchies, up to ${\cal O}(1)$ coefficients.
