Wingspan 14-16 mm.
Very similar to C. elongella, both species being quite variable. It is possible to identify either species from the foodplant if the moth is reared from the larva, but adults located in mixed habitat should be treated with more caution and may need to be dissected.
As suggested by the scientific name, the foodplant of the present species is birch (Betula), the larva mining the leaves initially and then living inside a rolled leaf in later instars.
There are two generations, flying in June and July, and then in September and October. The second brood overwinters as an adult and often reappears in the early spring.