Hi, I have checked my Indesign Document Setup and I definitely have the Australian A4 sizing set up yet every time i export the pdf it exports as an American letter. (Was only alerted when my printers called to query why i had the letter sizing).
InDesign Document setup is one thing - you can set your file to be A4 size.
But using the Page tool you can resize your page to another size - and you won't see that in the document size, the size is independent to that page.
Select the Page Tool and select the page - and take a look in the control panel at the top of the page to see what the dimensions are.
To reset your page to the Document Preset, then drag a Master Page to the page in the Pages Panel.
Let me know if that helps.
Thanks Eugene, that solved it. Much appreciated!