1. The Office's right to require payment of fees shall lapse after four years from the end of the calender year in which the fees became due for payment.
2. Rights against the Office for the refunding of fees or of sums overcharged by the Office shall lapse after four years from the end of the calendar year in which the rights arose.
3. A request for payment of a fee shall have the effect of interrupting the time limit specified in paragraph 1, and a written and reasoned claim for refund shall have the effect of interrupting the time limit specified in paragraph 2. After interruption the time limit shall begin to run again immediately and shall terminate at the latest six years after the end of the calendar year in which it originally commenced, unless judicial proceedings to enforce the right have been instituted in the meantime; in that case the time limit shall end not earlier than one year after the judgment has acquired the authority of a final decision.