Similar species: Birdsfoot Trefoil (Lotus corniculatus) - Very similar, but the flowers all radiate from a single point, and the leaves are quite different.
Yellow Vetchling is easily confused with Birdsfoot Trefoil (Lotus corniculatus)! But the flowers in Yellow Vetchling attach at various points along the stem. Whereas those of Birdsfoot Trefoil all radiate from a single point. Also the leaves are quite different.
Yellow Vetchling in its native habitat, a grown up meadow.