The latest opinion polls put it at around 11%, ahead of the Liberal Democrats, and Reform says it will have enough candidates to contest every seat.
In the last general election in 2019, the party did not stand in constituencies won by Conservatives in 2017.
The party currently has one MP, Lee Anderson, who defected from the Conservatives.
In his statement, Mr Farage said he had “thought long and hard as to whether I should stand in the upcoming general election”.
“As honorary president of Reform UK, I am fully supportive of Richard Tice’s leadership and urge voters to put their trust in him and Lee Anderson.
“I will do my bit to help in the campaign, but it is not the right time for me to go any further than that.
“The choice between Labour and the Conservatives is uninspiring, and only Reform have the radical agenda that is needed to end decline in this country.”
Reform has been particularly critical of the Conservatives on the issues of immigration and net zero.
Speaking after the election was announced, Mr Tice said Reform was ready for the election with “common sense policies”.
He added: “People know that the Tories have broken Britain. Labour and Starmer will do what they always do, which is bankrupt Britain.”
