Mikaela Mayer will fight in her fourth weight division in as many fights, though the move up the scale is for a good cause.

BoxingScene.com has confirmed that terms have been reached for Mayer to challenge IBF welterweight titlist Natasha Jonas. The bout is set for January 20 on a Sky Sports/ESPN+ show from a location to be determined in the United Kingdom.

ESPN.com’s Michael Rothstein was the first to report this development.

Liverpool’s Jonas (14-2-1, 9KOs) will attempt the first defense of the IBF welterweight title she claimed in an eighth-round stoppage of Kandi Wyatt on July 1 in Manchester, England. The win saw Jonas—a 2012 Olympic quarterfinalist for Great Britain—become a two-division titlist after a 2022 Fighter of the Year-level campaign where she unified three of the four major titles at junior middleweight.

The impressive run came as part of a three-division leap following her hard-fought, ten-round loss to undisputed lightweight champion Katie Taylor just one year prior. Their May 2022 clash saw Taylor prevail by narrow unanimous decision in a repeat of their 2012 Olympic quarterfinal match on the Irish superstar’s road to a Gold medal.

Jonas has won five straight since the defeat to Taylor, which came one fight after a ten-round draw with then-unbeaten WBC junior lightweight titlist Terri Harper.

Mayer (19-1, 5KOs) now embarks on a similar career path in her own bid to become a two-division titlist.

The 33-year-old American—a California native who relocated to Colorado Springs and now Las Vegas—held the WBO junior lightweight title for two years beginning with an October 2020 shutout of unbeaten titlist Ewa Brodnicka. Three successful defenses followed, including her ten-round victory over IBF titlist Maiva Hamadouche in their terrific November 2021 unification bout recognized by Boxing Scene as the 2021 Women’s Fight of the Year.

Her unified title reign ended with a disputed ten-round, split decision defeat to bitter rival Alycia Baumgardner in their lineal, WBC, IBF and WBO championship unification bout last October 15 in London. Mayer has since won two straight, both on UK soil.

She moved up to lightweight for a planned clash versus former 140-pound titlist Christina Linardatou, who was a late medical scratch from their April 15 clash when the BBBoC refused to license her due to the results of an eye exam. Mayer faced late substitute Lucy Wildheart, whom she defeated over ten rounds at Copper Box Arena in Hackney Wick.

In her most recent start, Mayer outpointed Silvia Bortot over ten rounds on September 2 in Manchester. The bout took place just above the junior welterweight limit, though Mayer disclosed the possibility of another move up in weight for her next outing which is now the case in her bid at another major title.

Boxing Scene has learned that the deal includes a rematch clause for Jonas, which could keep Mayer in the UK through 2024. The upcoming title challenge will mark her fourth straight in England after having fought exclusively in the U.S. since her August 2017 pro debut.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox