Originally Posted by
galawdawg
Since TAP is a member of the Star Alliance and BA is a member of oneworld Alliance, unless TAP and BA have an agreement on baggage handling, it is very unlikely that TAP will check your bags through. I understand they had such an agreement many years ago but I don't know the current status.
TP has a baggage interlining agreement with BA but that doesn't mean that they will check them through. Same is true for UA.