The show, which runs from March 5-8 2018, will now include a pre-registration tick box enabling visitors to have their say on the matter.
The BHA campaign argues that any reduced rate will stimulate investment, create employment and boost growth within the UK hospitality sector.
Research from Deloitte and Tourism Respect found that a reduction would contribute an extra £4.6b to HM Treasury over ten years and create 121,000 jobs.
The UK charges 20% on VAT for visitor accommodation, compared to 7% in Germany, 9% in Ireland, and 10% in Spain and Italy.
The Campaign to Cut Tourism VAT is calling for the tax in the UK to be reduced to 5% on accommodation and attractions.
Government affairs director for the BHA, Vernon Hunte, said: “Cut Tourism VAT is pleased to partner with Hotelympia and we look forward to speaking to delegates about how they can support the campaign.
“UK hospitality businesses compete on an unfair playing field with a Tourism VAT rate twice that of our European neighbours. 2018 is going to be crucial year in pressing home the case for a reduction.”
Hotelympia portfolio director, Ross Carter, added: “At a time of great uncertainty, British hospitality businesses need support from Government in creating an environment where they can thrive and prosper.
“With an independent treasury adviser attesting that such a reduction represents ‘one of the most efficient, if not the most efficient, means of generating GDP gains at low cost to the Exchequer’ Hotelympia 2018 supports this initiative wholeheartedly."