In a warm-up test before the European Cup, he made a try-scoring international rugby league début in Wales 13–6 defeat by Italy in October 2010. He scored again in his next international vs Scotland. In the final game of the tournament, Thomas was appointed captain, filling in for the injured Lee Briers. He scored a try in that game, helping Wales to a one-point win for both the European Cup Trophy and a spot in the 2011 Rugby League Four Nations.