Seven of the shows will take place in front of a slimmed-down live audience, 21 will be a mix of physical and digital, with the 50 remaining events taking place online only.
June's Fashion Week was held entirely online because of coronavirus restrictions.
The September shows are traditionally for womenswear but this year the BFC said it would be a "gender-neutral showcase" featuring men's, women's and mixed collections.
"LFW is one of the few international events to still be going ahead in London, proving the industry's resilience, creativity and innovation in difficult times," the BFC said.
The body said coronavirus restrictions provided an opportunity to reassess formula and innovate to maintain the industry's influence, particularly in terms of employment.
In 2019, the sector contributed £35 billion ($46.5 billion, 39.3 billion euros) to the British economy -- up 9.4 percent on 2018 -- and employed more than 890,000 people.
September's shows begin online with Burberry.
In June, the company was given a £573,000 government contract to make medical gowns and other protective equipment for frontline healthcare workers battling Covid-19.
