[HdS84]

Yes, but currently that's always the most expensive option. I am driving a lot from Cologne to Bremerhaven. Depending on the spot where I stop, I would need an EWE, EnBW, Aral, ionity, eon, shell or some smaller card to get somewhat reasonable prices. Annoying.

[ninalanyon]

Get yourself a Tesla account. I think all of the Tesla chargers between Cologne and Bremerhaven are open to any CCS compatible car; you just need the tesla app and register your credit card. Tesla is usually cheaper as well as more reliable.

But there are also services like ChargePoint which unify the payment systems for numerous networks (certainly including Eon and Shell).