Pay securely with an Android smartphone, completely without Google services: This is the plan being developed by the newly founded industry consortium led by the German Volla Systeme GmbH. It is an open-source alternative to Google Play Integrity. This proprietary interface decides on Android smartphones with Google Play services whether banking, government, or wallet apps are allowed to run on a smartphone.
For card (mastercard) nfc payments I use Curve pay on LineageOS with microG
I use it with GrapheneOS too. Perfect.
They rejected my application to open an account with them…
Yeah, I had trouble too but persisted and now it works brilliantly. I’m in the UK and it worked in Singapore, Australia and Japan.
Does it need play and/or services?
Yes; but I’m not logged in to any Google accounts.
It also works with MicroG (although the GrapheneOS guys don’t recommended using that).