Creating one design for both A4 and Letter Sizes

Hi There!

I'm new to the forum. I've been tasked with creating individual catalogue pages for a global company. Some divisions in the US use 'Letter' and here in the UK we use 'A4'.

I was wondering if there's a way of creating a one page design - say in A4 - that when exported as PDF will print to both page sizes? I wondered if I could set the print settings in advance so the page automatically prints to fit page? Unfortunately haven't been able to find any advice on this.

Any other suggestions would be very much appreciated.

Hayley