Serbia will replace Russia in the Davis Cup and Australia will replace them in the Billie Jean King Cup, governing body the International Tennis Federation (ITF) has confirmed.
Russia and Belarus have been suspended from international team competition following Russia's invasion of Ukraine.
Serbia and Australia are the highest ranked sides among the 2021 losing semi-finalists from each competition.
Slovakia and Belgium are also through to the Billie Jean King Cup finals.
Slovakia were due to play Australia in next month's qualifiers for the women's team event but will receive a bye, while Belgium receive a walkover as they were due to play Belarus.
The three sides will be joined by an as yet unnamed host, last year's runner-up Switzerland and the remaining seven winners of April's qualifiers in November's finals.
In the men's Davis Cup, a wild card for the finals previously awarded to Serbia will be handed to one of the 12 nations knocked out in the qualifiers earlier this month.
The 12 winning teams from the qualifiers, 2021 finalists Croatia and wild card Britain are the other confirmed sides for the finals, which will see 16 nations competing in four groups across four cities in September.
The top eight teams will advance to the knockout stages, which will serve as the season-ending event on the men's tennis calendar in a fifth host city at the end of November.
Russia won the Davis Cup and Billie Jean King Cup in 2021, becoming just the fourth nation to win both competitions in the same year.