Domestic and T20 Franchise Career

In December 2017, Seifert scored the fastest century in a New Zealand Twenty20 domestic match, and competed for Northern Districts against Auckland in the 2017–18 Super Smash. He made 100 runs from 40 deliveries.

He was the leading run scorer in the 2017–18 Plunket Shield season for Northern Districts with 703 runs in nine games. In June 2018 he received a contract with Northern Districts for the 2018/19 season.

In July 2020, he was named to the Trinbago Knight Riders roster for the 2020 Caribbean Premier League.

Tim Seifert IPL In October 2020, he replaced the injured Ali Khan in the Kolkata Knight Riders team in the 2020 Indian Premier League (IPL) but did not play a game during the competition. Tim Seifert IPL 2020 Team was Kolkata Knight Riders & kept in the Kolkata squad for the following season's IPL, but did not play until the league's suspension in May amid the COVID-19 pandemic. His departure from India was delayed after testing positive for the virus.

Tim Seifert IPL 2022 In February 2022 he was bought by the Delhi Capitals at auction for the 2022 Indian Premier League tournament.

International Career

In February 2018, Seifert was included in New Zealand's Twenty20 International (T20I) squad for the 2017–18 Trans-Tasman Tri-Series, making his debut for New Zealand against England on 13 February 2018. In December 2018, he was named in New Zealand's One Day International (ODI) squad for his series against Sri Lanka, who will make his ODI debut during the series in January 2019.

In August 2021, Seifert Cricketer was named to the New Zealand squad for the 2021 ICC T20 Men's World Championship.