Wingspan 7-9 mm.
Probably the commonest of the oak-feeding Phyllonorycters, this species is frequent throughout most of the British Isles.
At first glance the adult can appear devoid of markings, but on closer scrutiny, the pale greyish strigulae can be seen, as can the diagnostic basal streak, which extends more than half the forewing length.
The moths are on the wing in April and May, and again in August and September.
The larval mine is a small blotch on the underside of a leaf of oak (Quercus).