In an Instagram post, the barbecue brand said the toll of the last two years of Covid, compounded by the impact of the Omicron variant in December, had led its investors to pull out, and as a result the restaurant would permanently close on Sunday (30 January).
Hotbox adds that its sites at Market Halls in Fulham and Victoria would continue to operate.
The post said: "Hotbox started as an idea almost 10 years ago. The founding team travelled throughout Texas, hauled a 1 tonne smoker around East London and eventually found our first restaurant in an amazing property in Spitalfields.
"Seven years on from opening our doors we look back nostalgically to the innocence of just wanting to make the best barbecue we could. The joy in customers faces when they slathered our warm barbecue sauce all over their smoked ribs. Our brunches became an institution and you def all made the most of the ‘bottomless’ part.
"Sometimes you can smile even when there is pain in your heart…. It is with profound sadness that we will be closing the doors of our E1 restaurant. The last service will be this Sunday brunch and if any of you would like to join us for a last hurrah, we would be honoured.
"The reasons for closing are all condensed within the rollercoaster that has been the last two years. And after working so hard over the past six months to reinvigorate our business, the December debacle meant that our investors pulled out.
"We are so grateful for the time we had. You can still find us at Market Halls doing our best to create incredible smokey treats but for now, from our home, it’s goodbye."
Late last year, Hotbox opened a new site in Camden’s Hawley Wharf development, which subsequently closed in December.
Led by executive chef Lewis Spencer, Hotbox launched its Spitalfields restaurant in 2014 having previously traded at street markets in East London as part of Street Feast and London Union.