It is very limited - you can increase an SD parcel for up to 1kg to be
up to 2kg. That's all. And Tracked 24/48 is 0 to 2kg anyway, so it is
just rubbish. If your parcel is more than 4kg , which can happen after
packing to meet a customers needs, you cannot change a 2kg label to the
next level which is up to 10kg. Instead you have to call customer
services. Good luck!