[1] Known mainly for his batting skills, he made his Twenty20 debut for KwaZulu-Natal in the 2018 Africa T20 Cup on 15 September 2018.
[2] In January 2019, he was named as the captain of the South Africa national under-19 cricket team, ahead of their tour to India.
[4] He made his List A debut for KwaZulu-Natal in the 2018–19 CSA Provincial One-Day Challenge on 20 January 2019, scoring a century.
[6] Montgomery joined Nottinghamshire as a trialist in 2019 while studying at nearby Loughborough University.
[8] Montgomery made his County Championship debut in July 2022, going on to score 369 runs in eight First Class innings that season, including a career-best 178 against Durham, as the club won Division Two and earning himself a new three-year contract.