Kryton as JGG says it is a site mixed sand/cement render with an ashlar cut. Does the render sound hollow (boss) when tapped? In particular around the cracked areas. If it does then it would be best to remove and re-render.
I work for an external render manufacturer, one of the ones JGG mentions, if you need any advice feel free to email me.
EDIT – If it is a Victorian house it is possible that you have a lime mortar bonding the bricks and someone at some point has put a cement based render on top. Lime mortar doesn’t set as hard as cement and the cement render on top can crack due to the movement in the substrate behind. If that is the case then you would need a lime render or isolate the substrate from the render with a board or building paper.