<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by speedbird2018:
You could always use Online check-in, -24 hours before departure, if you have an exec card...if you don't, you can enrol instantly at www.BA.com
If you don't fancy OLCI, then most afteroon/ evening flights will be open for check in from -6 hours at the terminal</font>
Ah, once again, that quaint notion that you can "check in" prior to arriving at the airport (or at the rail station, in the case of Paddington and Victoria).
As a former airline employeee, involved in the departure process, I can tell you that you are not "checked in" until you are actually at the airport and the carrier knows that you are there - if you "check in" normally - i.e. at the check-in counters - and you fail to board your flight, they will go looking for you. If you use such features as "on line check in" and you fail to board your flight, they generally will not bother, they will let the plane go without you.
"Checking in" is meant to tell the airline that you are there, you are ready to go, that you intend to board the flight. Using OLCI the day before does not tell the airline this, and in any event does not take care of your baggage (going from LHR to SIN I presume there will be baggage).
Best bet is to get to Paddington as early as you can - 2 hours is, I think, the minimum - and check in there, they will take your bags and send them out to LHR for you.
Dave