France: the taux d'usure, republished every quarter
A French card balance is usually a credit renouvelable, revolving credit, and it is governed by the taux d'usure: a legal ceiling above which a rate is usurious and the lender commits an offence. The Banque de France publishes a new set of ceilings every quarter, derived from the average rate lenders actually charged in the preceding quarter plus a third.
Two things follow that surprise people used to a fixed cap. First, the ceiling moves: a rate lawful when the credit was taken out can be above the ceiling published three months later, and it is the rate at the moment of contracting that counts. Second, there is not one ceiling but several, banded by the size of the credit, with small credits allowed the highest rate. The figure the calculator opens on sits in the small-credit band, which is where most card balances fall.
Issuers typically require about 3% of the balance a month, with the interest taken from within that payment and a floor of about €15. Credit renouvelable is also subject to a statutory maximum repayment term, so a French revolving balance cannot legally run as long as the minimum-payment arithmetic on an American card implies.