An explanation is proposed to martensite inhibition beyond characteristic concentration thresholds in titanium binary alloys. The method combines the phenomenological theory of martensite crystallography (PTMC) and thermodynamic calculations (TCs) to describe the conditions under which martensite formation is favourable. It is shown that martensite can be crystallographically prevented while being thermodynamically favourable. The PTMC is implemented by taking into account the influence of composition. After a comprehensive comparison to experiments, two twinning systems and two glide systems are inferred to be able to produce the lattice invariant shear. The critical concentrations above which martensite cannot form are computed and compared to experimental results on binary and ternary systems, showing good agreement. The proposed method may be used as a guide to design titanium alloys for controlled martensitic behaviour.