What I was wondering after reading the article: How does Mulvad actually decouple banking data from the account ID? Or is it as simple as verify transaction once but never log?

I think they remove the invoice after a month. You can also, send them cash in an envelope

So there's no subscription thing going on, you just manually pay invoices?

I once spent an entire year issuing chargebacks on AWS charges coming from god knows what AWS account. Most likely some client project I forgot about and didn't have the login to anymore, who knows. Makes me think about that - for a service where you can't login if you lose the credentials, how do you cancel a subscription? In my case I had to eventually just cancel the credit card and get a new number.

No subscription. It’s pay as you go. You top up $X and you get X months. That’s it. If your month expires, it expires. Just top off and you’re good to go.

You can pay with an envelope of cash, so they don't need your banking data to begin with.

Perhaps so, but that's damn difficult or very risky for all but a very select few.

Because you can't mail cash? Or it won't be delivered without a return address