Up to 15,000 supporters will be allowed to attend the Kingspan Stadium for Ulster's opening three competitive home games of the upcoming season.
It means the Belfast venue could be just 3,000 fans short of full capacity for the matches in the new United Rugby Championship.
The fixtures are against Glasgow on 24 September, Benetton on 8 October and Emirates Lions on 15 October.
Stadium bars will be allowed to operate, with one-way traffic flows.
Ulster welcomed 10,000 fans for a friendly against Saracens earlier in September, the first time substantial numbers had been permitted in the ground since February 2020 as a lot of last season's games were played behind closed doors due to the Covid-19 restrictions.
The success of that pilot has led to an allocation of 15,000 tickets for these three matches, at which all stadium seats will be available and terraces will operate at 75% of normal capacity.
Face coverings must be worn when moving around the stadium and in any indoor areas.