There is a regular bus service between Hereford, Hay on Wye and Brecon operated by Stagecoach UK Bus.
The 39 service operates several busses per day in each direction between Hay on Wye, Hereford and Brecon, Monday to Saturday. On Sundays and bank holidays there is a more limited service. A timetable for the services can be found on the Stagecoch UK website.
The bus journey between Hereford and Hay on Wye typically takes 1 hour. The bus journey between Brecon and Hay on Wye typically takes 45 minutes.
There is a taxi stand outside the main entrance to Hereford railway station from which taxis to Hay on Wye may be obtained. The journey takes approximately forty minutes. Note that the journey from Hereford to Hay on Wye by road from the railway station is about 23 miles and, depending upon the time of day, the taxi fare for this journey may be in excess of thirty pounds in each direction.