Ralf-Aquamarine-Unicorn For Joint bank accounts 1/2 the balance will be used for your personal interest calculation. (When you have more than two account holders then divide by the total number of account holders).
What John is referring to is the Joint memberships. For a Joint Membership the max. eligible balance is still €10.000.-, but, let me show how this works by means of an example;
Imagine you have both a personal IBAN (no other account holders) with €7500 and a Joint bank account (with three other account holders) with €2500
With a Premium membership you would get interest over the first 10.000 euro. That would mean in this case you get interest over €7500 (your personal IBAN) + (25% of €2500) = €8125.
Say you are in a Joint Membership (with three other people). Then the membership still gets interest over the first €10000, but now there are multiple people in the membership, so each individual taking part in this membership get 1/4 of €10000 (= €2500) for interest calculations (total amount of membership participants is 4 in this example). Meaning you'd get interest over €10000 (personal IBAN) + (25% of €2500) = €8125, which is higher than €2500, so for interest calculation this amount will be capped to €2500 over which you will earn interest. So, having a Joint or Pack subscription will give you some discount of the monthly fee, but the cap on the balance eligible for interest is lower depending on the amount of participants in your membership.
I hope this example was somewhat able to clarify things. 👍😁