Video assistant referees will be used in the Champions League and Europa League this season, Uefa has announced.
The technology was scheduled to be first used in the competitions from next season.
But Uefa says it will be brought in from the last-16 round in the Champions League and in the Europa League final.
VAR will also be used next year at the Nations Leagues finals and in the finals of the European Under-21 Championship.
"We are ready to use VAR earlier than initially planned and we are convinced that it will be beneficial for our competitions as it will provide valuable help to match officials and will allow us to reduce incorrect decisions," said Uefa president Aleksander Ceferin.
VAR was used at the 2018 World Cup and will be introduced in the Premier League for the 2019-20 campaign.
The first of this season's Champions League knockout matches will be played on 12 February 2019, with the Europa League final on 29 May.
England will be taking part in the Nations League finals in Portugal during June, along with the hosts, the Netherlands and Switzerland.
VAR will then be used from the play-off stage of the Champions League next season as well as in the 2019 Super Cup.
A statement from European football's governing body added: "Uefa still plans to subsequently extend the use of VAR at the final tournament of Uefa Euro 2020, in the 2020-21 Uefa Europa League (group stage onwards), and in the 2021 Uefa Nations League Finals."