SUCCESS!! (so far anyway, my new Vodafone UK SIM is activated!)
Note: I activated the SIM in an older phone, not my current phone. I'll use "the old phone" with the Vodafone plan when I'm "out and about" - mostly for data - and keep my "new" phone for use in the hotel room with (free) Wifi calling and wifi texts back home. (I made this decision so that I'm not having to swap SIM cards to alternate between Vodafone UK services and my normal US carrier.)
ACTIVATING THE Vodafone UK SIM from the US
I received my Vodafone UK SIM today, 4 days after ordering it (for $4.00) on ebay from a US-based seller. It's taken me about an hour, a few nervous moments (some of the reviews I read said it couldn't be done!) and a few Google searches - but I have received the (free) confirmation text from Vodafone UK as the final step allowing me to activate my SIM card and register it online with Vodafone UK!
Next step: "top up" the card with some credit, which I'll do nearer my September departure date.
THE TECHNICAL DETAILS
This process was "simple" but not for the technically faint of heart. I had to do some research to:
1) Find the Vodafone APN network settings (thank you Carphone Warehouse!)
2) Find the steps to set the right network mode for my device
Note: Vodafone lists LOTS of devices (Android and iPhone) and the specific instructions for each. The instructions for my phone were near-perfect and I only needed a tiny touch of common sense (or was it a good guess?) to make it work.
Within minutes of completing those steps, I received a (free) text from Vodafone with the security code needed to activate my SIM and account online. I was successfully able to set up a MyVodafone account. With that account, I should be able to:
- "top up" my account online with credit using wifi
- (optional) add a credit card to my account to simplify future top-ups, or add the CC details manually each time
Note: because my Google account is in the US, I am unable to download the MyVodafone (UK) app. I could create a UK Google account, but the online access to MyVodafone seems easy enough that I'm not going to bother.
I must once again thank Andrew H for giving me the courage to try this technical feat! Even though I decided to try Vodafone UK, rather than his Dutch Vodafone recommendation. I think I figured this process could be tricky enough for me to follow, without having to translate from Dutch!