DeG, I think Wiki might have got that wrong.

I'm a UK accountant, and in the world I'm obliged to inhabit, a billion has always been determined as one thousand x one million.

I've always understood that a million-million is the US definition of a billion.

Someone out there please tell me - am I correct, or have I laboured under a mis-conception this past 45 years (and possibly bankrupted a lot of people?) :-)