Thanks, this was very helpful.
Originally Posted by
corporate-wage-slave
It's in the Lounge Access guidelines, via the BA Forum Dashboard.
As a oneworld Emerald - one guest for First Wing and Flounge.
As a First traveller - one guest for First Wing and CCR.
The guest needs to be departing T5 the same day for the gates to work, but that's the only requirement. It's not practical to use First Wing if unaccompanied, but you can guest at the lounge entrance if arriving separately.