The capacity of the Olympic Stadium is being increased by 6,000 to 60,000, West Ham confirmed on Thursday.
Season ticket demands had well exceeded the seats available for the Premier League club, who are flying high in fifth in the table this season.
With that, West Ham said they had worked with stadium partners to maximise the number of seats available - leading to the announcement of the increase ahead of the move before the 2016-17 season.
West Ham vice-chairman Karren Brady was delighted, saying: "Today's announcement is further evidence of the upward trajectory of this club.
"We are on course for what could be our most successful Premier League performance ever and our ambitions to finish in the top six and break into Europe are very much within reach.
"West Ham fans are famous the world over for their wonderful support. They have demonstrated this once again at matches this season and in the way that they have embraced the move to the new ground.
"We are delighted to be able to reward that magnificent support by releasing additional season tickets and bring even more visitors to the park to enjoy all that it has to offer.
"The 2016-17 season looks bright for the team, the club and our fans. Not only will we have one of the world's greatest new stadiums, but now it will be one of the very largest in the world's most-watched league - a stadium with both the quality and the capacity to match our ambitions."