Charged lepton flavour violation (cLFV) is a flavour-changing short-range interaction among charged leptons. The cLFV processes, although allowed by neutrino oscillations, are highly suppressed in the Standard Model (SM). Since their occurrence is below any current experiment sensitivity, observing a cLFV process would constitute a clear probe of physics Beyond the Standard Model (BSM). The LHCb collaboration has conducted searches of cLFV decays involving different lepton flavour couplings and set the most constraining upper limits on the branching fractions of 𝑏 → 𝑠𝑙𝑙′ transitions, where leptons with different flavours are direct products of the decay of 𝑏-quark mesons. They allow boundaries to be set in the parameter space of various BSM models.