No. Regional vs mainline has nothing to do with destination. They are separate airlines. At LHR bmi have two lounges, one is physically reachable by all as it is in the main part of the departure lounge. But bmi designate this one for passengers not going on flights to the UK and Ireland. The second lounge is after the security point separating back out passengers going to UK & I destinations, so is designated for them. The UK & Ireland have a common travel area between them, despite being separate countries. As a result this lounge can only be used by people going to UK & I. [The main departure lounge area is mixed ('UK&I plus non-UK&I), people staying within UK & I are photographed upon passing through main security, this photo is then checked when they elect to leave the main departure lounge and head towards the UK & I gates, which is where the bmi lounge you mention is located. The photograph helps ensure border security given that arrivals from within the common travel area can generally walk straight out of the airport, passengers connecting to common travel area flights will have passed through imigration (but not customs) before reaching the departure lounge for their flight within the CTA.] bmi mainline operate a320 series and larger aircraft and are based mainly at Heathrow (some wet lease services operated for others don't go to or from lhr at all). Bmi regional operate smaller aircraft, are a separate company and are headquartered in Aberdeen and fly from various locations in the Uk to elsewhere in the uk and abroad. Having said that, bmi regional with their smaller aircraft do operate some services at some times for mainline, and they also fly their own services to lhr. Destinations really have nothing to do with it, nor lounges.