For my wedding ring I bought what was at the time called a Kerv Ring (now known as a K Ring due to a trademark conflict). This is a contactless payment card in ring form, which allows you to pay for things and use the tube without getting a card out.
The ring itself is rather attractive and comes in a range of colours. It works great as a ring and is waterproof. However, the user experience of making payments leaves something to be desired. Sometimes the ring fails to read due to proximity but the main issues are on the backend.
It is implemented as a virtual prepaid mastercard that the ring is linked to and this needs to be regularly topped up, which can be automatic. This means that it’s not directly linked to your bank account with individual transactions like a normal debit card and it’s not accepted by some retailers.
This wouldn’t be too bad if the website was easy to use but it is far from polished. There are many UX sins such as disabling pasting in input fields and failing to URL encode links in emails.
Fortunately this can all be fixed and enhanced in software if it’s invested in. For example, it would be great to get instant notifications on my phone when making a payment like some startup challenger banks offer. SMS doesn’t cut it and the weekly balance updates just get annoying.
Perhaps the best outcome would be for a company like Monzo or Starling to integrate K Ring into their product like a Dutch bank has. Until then I’m going to investigate the potential for the ring’s use in home automation with some NFC readers.
However, it’s good that no bank account is needed to use K Ring. Electronic payments often exclude those without bank accounts and I would support laws to require cash as a valid payment method at all physical retailers, as it is for debts (such as what is being considered in New York).
As it’s my wedding ring it is kind of awkward to use on the tube, where the card readers are on the right of the gates. Although I avoid the tube whenever possible because it’s rarely a pleasant experience.
The best way to pay for a journey in London is with an unregistered Oyster card (or cards) only topped-up with cash. This helps to avoid leaving a data trail tied to your identity. Make sure to turn off your WiFi too, particularly if the MAC address isn’t randomised.
The best thing about the ring is its novelty value. For example, when I use it to buy a round in the pub the staff often want to show it to their colleagues. We will see how long that lasts.