In the West Midlands you can board for free from 9.28am and the machine always accepts passes from that time onwards. Before that time in the West Midlands National Express have a £1 fare for disabled/older person pass holders.
But you still get people chancing it from about 9:20am onwards.
When my mother lived in Poole, her local bus (Breezer 60) had an hourly service which departed from her stop at 24 minutes past the hour, so too early for concessionary pass users. But due to traffic delays and inadequate running time being allowed, the bus was often late, arriving at the stop after 09:30. All the "twirlies" cottoned on to this and would hang around the bus stop hoping that it was sufficiently late so that they could use their passes. Of course every so often miracles would happen and the bus would arrive on time, resulting in sometimes heated arguments.
The law does allow bus companies and local authorities to designated a journey that starts before 09:30 as off peak, if the frequency is such that making people wait for the first post 09:30 journey would cause hardship or an excessively long wait, as in the example above from Woking.
