In October 2021 Richardson was named as part of the Scotland training squad for the Autumn nations series, for which he was eligible because his father was born in Scotland.[4] He was subsequently selected for the 42 player full squad for the series.[5] On 18 November 2021 he was named as a replacement for Scotland in their match versus Japan on 20 November 2021.[6] He came on as a second-half substitute to win his first cap in that match which Scotland won.[7]