So activated the NFC setting on my phone to do so but not a clue how to use it, got the secure sim from AT&T for my Lumia 920 and did update to wp8.1
You should be able to just tap a NFC tab at the checkout counter and it should ask for your PIN.
First of all, you need a SIM with a secure payment element, which you almost definitely do not have unless you specifically ask for it. Second, in 8.1 I believe the payment stuff is not offloaded to an app (my guess is in order to enable things like Isis) so I think you need to wait for that app.
I assume you mean that it will be offloaded?
Fat chance of anyone actually being able to use tap to pay if it relies on mobile operators then ISIS has been around for years already and all we have is a vague hint of two US operators thinking about maybe trialling it...
Isis went nationwide late last year, with support from AT&T, Verizon, and T-Mobile.... Now, the issue is the app needed only supports IOS and Android atm.... but they did mentiontion WP8 support, and it was even mentioned when the Lumia Icon launched.
To get your secured sim....
https://www.paywithisis.com/get-sim.html
Isis went nationwide late last year, with support from AT&T, Verizon, and T-Mobile.... Now, the issue is the app needed only supports IOS and Android atm.... but they did mentiontion WP8 support, and it was even mentioned when the Lumia Icon launched.
To get your secured sim....
https://www.paywithisis.com/get-sim.html
Sadly, the USA is only one very small part of the world in the grand scheme of things...