Originally Posted by the810

I can't comment on the US but every single delayed bag delivery I had in Europe came the next day after the bag has arrived at the airport as long as it was a local delivery (which are normally done by the dedicated airport service). The only time it took 2-3 days was when I needed the bag delivered 200 km away (arrival to BUD, delivery to Bratislava and by the time we created PIR, it was too late to reroute the bag to VIE) and it was sent via "generic" courier service.

I'm not saying that LHR is the only airport with these issues, but it's most definitely not among the better ones if the bags take three days to arrive to London.