  The growing experimental indication of Lepton Flavour Universality Violation
(LFUV) both in charged- and neutral-current semileptonic B-decays, has
triggered many theoretical interpretations of such non-standard phenomena.
Focusing on popular scenarios where the explanation of these anomalies requires
New Physics at the TeV scale, we emphasise the importance of including
electroweak corrections to obtain trustable predictions for the models in
question. We find that the most important quantum effects are the modifications
of the leptonic couplings of the W and Z vector bosons and the generation of a
purely leptonic effective Lagrangian. As a result, the tight experimental
bounds on Z-pole observables and tau decays challenge an explanation of the
current non-standard data. We illustrate how these effects arise, by providing
a detailed discussion of the running and matching procedure which is necessary
to derive the low-energy effective Lagrangian.
