There are two species of the genus Nothochrysa in the British Isles:
Nothochrysa capitata and Nothochrysa fulviceps
The British species of Nothochrysa share a rectangular intramedial cell (IMC) and a bright orange head.
Nothochrysa capitata
This species has the shared genus features (rectangular IMC and bright orange head), in addition to the defining features of the top of the thorax being red-brown without a pale stripe and the tarsal claws being simple.
Nothochrysa fulviceps
This species has the shared genus features (rectangular IMC and bright orange head), in addition to the defining characters of the top of the thorax having a wide pale stripe and the tarsal claws having a tooth.