Evolutionary states of the donor stars at the onset of mass transfer. For each type of donor star, three bars are shown, with the left representing model OBin, middle model T14, and on the right model E09, similar to Fig. 8. With colour we indicate when the donor star would initiate mass transfer if the inner binary would be isolated: from the bottom to the top, on the MS (blue), HG (yellow), RGB (green) or AGB (red), or if mass transfer happens at all (if not: purple). Overall, the onset of RLOF is expedited due to the presence of the tertiary star and the frequency of case A mass transfer increases by a factor 3.7–5.5.