At the bottom of the Adobe webpage click on Products. Then scroll down to LR and click on buy. You can select the update option.
When I type www.adobe.com, it detects I am in the UK and changes the link to www.adobe.com/en, and this is an error page. At the top you get the 404 message, but there is a list of links, including Products. The only place Lightroom appears is under Creative Cloud. It's also not available on Amazon.co.uk but is available for $149 on Amazon.com - but only if you fulfill certain conditions, chief of which is living in the USA.
These are the reasons I asked the question. I've been all over Adobe and the website is very light on content, so it's not even easy to find out what the rules re Creative Cloud are. I can understand why Adobe might put Photoshop in the cloud, but they still have Elements. I can't understand why they restrict the freestanding product to the US.
I managed to buy the stand alone product from the Adobe UK website yesterday morning. On the Lightroom page there was an option in the bottom right hand corner for Lightroom 6. I clicked on the link which added the product to the cart, and then I clicked on "Full", which gave a drop down version for Upgrade, which was priced at £59.09 or something like that. I then completed check-out, downloaded the product and used the code that was emailed to me.
The install went OK, apart from not auto-detecting my existing Lightroom 5 licence (cue me rummaging through cupboards for my installation CD). However once installed it had picked up all the preferences from lightroom 5?
I will admit that it wasn't easy to find, and I could only find the link on my desktop computer - when browsing using an ipad the link simply wasn't there.
Edit - search for all products, you will see Photoshop Lightroom 6, click on Upgrade, and then add to cart
Thanks John Beardsworth. I was just about to post to John Stewart that I can't get to the page he displayed. There isn't any way that I could find to get to the right page without the complete link.
I can now see the 'Buy' button. £103.88 including VAT. I'm guessing that I need to buy outright as I'm only on LR4. Would I be right in assuming I would have to first buy an upgrade to 5 and then buy an upgrade to 6? If that's even possible it probably won't save me much.
Guess I'd better act before I lose that precious link
Don't rush.....you CAN buy the upgrade from LR4, so make sure you select that, NOT the full version (and no need to buy/install LR5 first).
So you can! Once you choose to upgrade you get asked which version you are upgrading from. £59.99. Lovely. Thank you all very much for your quick and accurate responses