(1) Where a person has a business relationship with a merchant such that the reciprocal claims and performance, plus interest, arising from the relationship are placed on account and balanced at regular intervals by set-off and by determining the resulting surplus in favour of one party or another (revolving account, current account), the person to whom a surplus is due upon settlement of the account may demand interest on the surplus due from the account settlement date, also insofar as interest is included in the account.
(2) Accounts are settled once per year, except as otherwise provided.
(3) In cases of doubt, the revolving account may also be terminated at any time during the term of an accounting period, with the effect that the person to whom a surplus is due pursuant to the account may demand payment thereof.