  The observed branching ratios for $B\to K \eta'$ decays are much larger than
factorization predictions in the Standard Model (SM). Many proposals have been
made to reconcile the data and theoretical predictions. In this paper we study
these decays within the SM using flavor U(3) symmetry. If small annihilation
amplitudes are neglected, one needs 11 hadronic parameters to describe $B\to
PP$ decays where $P$ can be one of the $\pi$, $K$, $\eta$ and $\eta'$ nonet
mesons. We find that existing data are consistent with SM with flavor U(3)
symmetry. We also predict several measurable branching ratios and CP
asymmetries for $B \to K (\pi) \eta(\eta')$, $\eta(\eta')\eta(\eta')$ decays.
Near future experiments can provide important tests for the Standard Model with
flavor U(3) symmetry.

High Energy Physics - Phenomenology