We investigated the effect of F on the electrical activity of B-doped junctions in preamorphized Si. It is shown that while the carrier dose introduced by B is reduced in the presence of F, no indication of B–F complexes formation can be found and B maintains its full substitutionality. Investigations on F-enriched crystalline Si demonstrated and quantified the n-type doping of F. These results clarify that the loss of holes in junctions coimplanted with B and F is not due to a chemical interaction between B and F, but simply to a dopant compensation effect.