Wingspan 5-6 mm.
Like many of its congeners, this species is more easily identified by the structure of the leafmine created by the larva. In this case, the foodplant is beech (Fagus sylvatica), and the mine is a sinuous gallery with the frass forming a coil part way through the mine.
The species is fairly common over much of Britain, flying in two generations, April and May, and later in July and August.
The adults are small and dark, with a pale patch centrally on the forewing, and with a wingspan of only around 6mm.