The use of the hypervalent iodine reagents in oxidative processes has become a staple in modern organic synthesis. Frequently, the reactivity of lambda(3) iodanes is further enhanced by acids (Lewis or Bronsted). The origin of such activation, however, has remained elusive. Here, we use the common combination of PhI(OAc)(2) with BF3 center dot Et2O as a model to fully explore this activation phenomenon. In addition to the spectroscopic assessment of the dynamic acid-base interaction, for the first time the putative PIDA center dot BF3 complex has been isolated and its structure determined by X-ray diffraction. Consequences of such activation are discussed from a structural and electronic (DFT) points of views, including the origins of the enhanced reactivity.