Luggage allowance
 

I am flying from Shannon to Heathrow with Aer Lingus to connect with a flight to Adelaide via Singapore with Singapore Airlines.My ticket was booked with Singapore Airlines but as they don't fly from Shannon they are using Aer Lingus for the connection.
Aer Lingus allow 23kg of checked luggage on their long haul flights but the Shannon to Heathrow leg is classed as short haul.Will the fact that i am connecting to a long haul in Heathrow allow me to take the 23kg or will I be restricted to 20kg

Check Singapore Airlines website for a FAQ or baggage section to see their answer on it. I'm fairly sure that the airline you booked with, Singapore, is the one whose baggage restrictions apply, but don't want to tell you that for certain.

On a side note though, does it even matter? 20kg is 44 pounds and 23kg is 50 pounds. Will you really have a bag that's over 44 pounds to check? If your bag is under that amount anyway, it doesn't matter whose policy is in effect. Even when I check a fully packed bag, it usually doesn't top 40 pounds even on the way home with all of my purchases.

Thanks, but my wife seems to think that they don,t have shops in Australia and she wants me to take half a department store to our daughter who lives there

I'm no expert, but wouldn't you have to follow the restrictions of the plane you're actually ON?

When booking a continuous domestic-to-international fare in the U.S., the rules for the international flight usually apply. But I've often seen confusion and problems. My advice is to call Aer Lingus and see if they can give you a straight answer. My guess is they will not and you may be asked to pay the checked baggage fee in Shannon. But it's very possible that the EU has rules on this.

In any case, to avoid problems, limit your bag to 20kg and simply take less.