Re: Renewing UK passport when living in Switzerland
As far as I'm aware you can ONLY do it online now. But no, no-one from the passport office told me that; however, I imagine that with Covid they won't be encuraging people to go personally to the office. You might like to check with them - IF you can reach them by phone or e-mail.
On the technology, if it reassures you, I am 62 and an e-dinosaur, but it really isn't difficult. I went to a little photo shop right on the Plainpalais tram stop - I think it's called Pricam - to get the photo. I told them I needed a digital photo for a UK passport application. They give it to you on a USB stick, all you need to do is shove it in your computer and do the upload. Easy-peasy. Then it's two or three questions and that's all. You don't need to have the code on the photo that they're talking about, it's not obligatory. I"m sure you can do it, but if it's a bit hard, perhaps a younger, tech-savvy friend or relative could help! :)
More than a month at the moment, I think. I sent my old passport on 13th July and it didn't reach them until 29th. They update you on progress by e-mail.
As I said, IF you hold another nationality as well (say Swiss, like me) you have to send colour photocopies of every page of your other nationality passport. If you don't, you just send the old passport in an envelope to the address they give you. You make the payment and upload the photo online.
Hope that helps!