How does late payment of maintenance fees affect others’ rights?
Late payment of maintenance fees can affect the rights of third parties who acted during the period when the patent was considered expired. MPEP 2501 states:
“A patent, the term of which has been maintained as a result of the acceptance of a payment of a maintenance fee under this subsection, shall not abridge or affect the right of any person or that person’s successors in business who made, purchased, offered to sell, or used anything protected by the patent within the United States, or imported anything protected by the patent into the United States after the 6-month grace period but prior to the acceptance of a maintenance fee under this subsection, to continue the use of, to offer for sale, or to sell to others to be used, offered for sale, or sold, the specific thing so made, purchased, offered for sale, used, or imported.”
This means that if someone began using the patented invention after the patent was considered expired but before the late maintenance fee was accepted, they may have certain rights to continue their use.
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