Kammala jumla mai zuwa: A Euro 2016, Allen ya kafa burin Aaron Ramsey a nasarar da suka yi a kan Rasha a ranar 20 ga Yuni, wanda ya bai wa Wales damar zama ta farko a rukunin su kuma ta ci gaba zuwa zagaye na zagaye na gasar. An fitar da Wales bayan rashin nasara 2 zuwa 0 ga Portugal a wasan kusa da na karshe a ranar 6 ga Yuli. An kira Allen zuwa ga tawagar gasar don wasan kwaikwayonsa. A watan Mayu 2021 an zaba shi don tawagar Wales don jinkirta
Gasar cin kofin Turai ta 2020.