That's mental! Suppose you literally were just going to a registry office and not really making a big deal of things. How do you prove that? Do you just send an email confirming date you're going?
That's exactly what we did haha! Yes, I had copies of emails from enquiring about dates, and emails about wedding photography. I also had the receipt for my dress (it was from David's Bridal so I was lucky it said that in big letters at the top!)
They just want to know you are planning something but you dont have to actually have booked a solid date. They seem to understand the process involved and for us it was crazy. Registry Office did not want to book anything until we had booked our giving notice appointment, which was a two week wait for and we couldnt book until I knew when I could be back in the country, then you have to wait 28 days before you can get married. We ended up having our wedding two weeks after the date we originally wanted, but it doesnt matter,, as long as you marry within six months!