© 2019, The Author(s). Using pp collisions corresponding to 3 fb −1 integrated luminosity, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, the ratio of branching fractionsℬ(Λb0→ψ(2S)Λ)/ℬ(Λb0→J/ψΛ)=0.513±0.023(stat)±0.016(syst)±0.011(ℬ)is determined. The first uncertainty is statistical, the second is systematic and the third is due to the external branching fractions used.[Figure not available: see fulltext.]