KMC….The ITA tool VK has referred too is brilliant.
He is also right that it takes some effort but once known then a single entry can reveal what the cheapest starting point is for a flight. For example if you want to fly BA and not pay the ludicrous UK fares then start in Europe ( if you have the time and inclination). AMS LHR JFK can be had for £1200 often including the LCY flight via Shannon. On ITA if you enter as the originating point:
In departing from enter this string exactly.
Click advance routing codes and enter
and in the destination box your final destination.
In advance routing box again type BA BA
Select dates number travelling and then select class of travel
In city sales box change to LHR to get prices in £
ITA will provide the lowest fares for each of the points listed.
Have just done this for 1st June to JFK and back 15th.
EX LHR BA cheapest is £3624
ITA show ex
ATH at £1708
There are over 50 options less than £2000 and over 150 less than £2500 all saving a huge amount over the LHR Fare.
Once you decide remember to factor in flight to starting point….you must originate as ticketed…… Even so the LIN fare represents a saving of almost 50%.
ITA cannot book or ticket…yet…….but this is a google company so who knows.
Booking for BA flights is done on BA.com and simply change country to that where you will originate. Fares are in Euro and charged to crdeit cards in Euro.
If you have time and want to travel comfortably for less on BA, then this is a very easy means of doing so.
The cheapest cities are normally ( but not always) IST, MXP, LIN, FCO,AMS, ARN, HEL ATH. For family holiday paid just £7000 for 4 to far east in club and same flights dates and times ex LHR were £21000 on BA.com.