Billy Taylor

 is one of the main characters of The Halcyon, portrayed by Ewan Mitchell. He's the bellboy at the Halcyon Hotel and Peggy Taylor's son.

Character Overview
If Billy had a Downton Abbey equivalent he would be William Mason, the earnest First Footman who was in love with Daisy but went off to war and came back in a box. In this case, Billy is a bell-boy whose mother Peggy (Liz White) works on the switchboard. He's turning 18 and is desperate to go off to war, though mum is worried he'll be cannon fodder. It looks like he also has a secret passion for Kate, a maid at the Halcyon.