(1) A patent lapses if
1. the proprietor of the patent surrenders it by written declaration to the German Patent and Trade Mark Office, or
2. the annual renewal fee or the difference is not paid in due time (section 7 (1), section 13 (4) or section 14 (2) and (5) of the Patent Costs Act (Patentkostengesetz), section 23 (7) sentence 4 of this Act).
(2) The decision as to whether the payment has been made in due time lies solely with the German Patent and Trade Mark Office; sections 73 and 100 remain unaffected.