After representing England at U18 and U20 level, Vunipola was called up to the England Saxons Squad in January 2013. He trained with the England Squad during the 2013 Six Nations Championship and made his senior England debut during the England tour of Argentina in the test against Argentina in Salta in June 2013, coming off the bench to score a try in England's 32–3 win. Earlier in the tour he played in an uncapped match against a Consur XV, and scored a hat-trick of tries in six minutes.