Originally Posted by The _Banking_Scot

Hi,

Thanks for that.

Here is my thoughts on the timings ( assuming an ontime arrival on stand at LHR @1530 and ability to use e-gate immigration- depending on your passport type/origin)

1615 Cleared immigration and collected luggage (also depending on where your TXL-LHR flight arrives- if at the C gates it could take longer but likely to be B or A gates
1625 At the Heathrow express platform ( need to get a voucher for free transit between terminals) or Underground ( free if you use Oyster or contactless)
1645 Get the underground or train ( Muphy's law paraphased suggests that if you are in a hurry you will just miss a train)
1650 Arrive at Heathrow T2/T3 Underground train station
1700 Arrive at T3 CX check in

This should give you about 2 hrs 10mins before CX check in closes at T-60 ( 1910)

However if you have a passport that cannot use the egates immigration can take a lot longer which will eat into the time

Depending on your BA ticket type if there are problems on the day you may be able to do a same day change ( SDC) for a fee ( check the BA forum for details )

Regards

TBS