Originally Posted by
corporate-wage-slave
It's 20 minutes in theory, and all boarding passes will say that for WAW and everywhere else (except EDI which is 30 minutes as printed, but still 20 minutes as SOP). The one place that routinely flaunts this is LIS, where they can and will close at 30 minutes, but they are not supposed to do this. Services to LHR cannot leave more than 10 minutes early anyway.
Closing the door at T-30 for a shorthaul narrowbody seems crazy, though part of that might be frequent WN flights in the US. WN publishes a boarding time of T-30 for all domestic flights, but in practice that's only for the 175 seat planes. Commencement of boarding for the 143 seat 737-700s is in fact T-25. International flights board at T-45.