The article says the QR check-in in the neighbouring state of Victoria works offline, but it didn't for me a couple of months ago when I lost 4G signal. Perhaps it's been changed since then – one would hope so, given the existence of mobile blackspots in rural Victoria.<p>However, the way the codes are used in Victoria is different, which means the size of the QR code doesn't matter much. (They tend to be about 1/4 of an A4 sheet, so larger than in NSW.) No-one is checking your phone to ensure you checked in; rather, it's an honesty system. So the codes are generally in the window near the door, and you stand off to one side. In those circumstances, if the code were larger and you could stand farther away, it would actually be less safe because it might encourage more than one at a time to use the code. As it is, a queue forms with polite distancing, like an ATM. (Remember those, and cash?)<p>We also have QR codes at every tram and bus stop in Victoria, as laminated A4, so they definitely do need to work outside. I haven't used those, but ones in shop windows work fine when it's raining. The only problem I ever encountered was a QR code on a bendy laminated piece of A4 indoors, under coloured lighting.<p>Vaccination status is integrated with the Victorian app, because it was that state that was tasked to work with the Federal government to implement and (together with the NT and Tasmania) test that. It is currently undergoing testing in rural Victoria, although anyone in the state can load their Federally-issued vaccination certificate into the app. NSW have not yet taken the code and put it in their app, probably because the people doing that expected the restrictions to be eased on the original timetable.<p>While loading the certificate into the apps should be technically simple, it isn't, because of 1980s Federal laws to do with sharing of medical data. (They know my phone number, Victoria knows it, but it is against the law to match it. I must log in to the Federal site or the Federal app on my phone and authorise it to copy the certificate into the state app, and I must keep doing it every few months.)