What to do next
Establish whether it lapsed or expired
A lapse is a failure to maintain, and may be reversible. Expiry at the end of the statutory term is final. The remedies are completely different, so confirm which has happened before anything else.
Check the reinstatement window and its test
Most offices allow reinstatement within a defined period on payment of the outstanding fee plus a surcharge, and many require a statement that the failure was unintentional or that due care was taken. The window is finite.
Assess intervening rights
Someone who began using the invention in good faith during the lapse may be entitled to continue, even after reinstatement. That can materially reduce the value of reviving the patent, and it is worth knowing before you spend on reinstatement.
Fix the process that caused it
Lapses are almost always administrative. Confirm who is responsible for the renewals docket, whether an annuity service is engaged, and that the office holds a current address for correspondence - a change of address is a common root cause.
Plan for genuine expiry
As term end approaches, consider what else protects the product: trademarks and trade dress, trade secrets in the manufacturing process, continuing improvements protected by later filings, and regulatory exclusivities in life sciences. A single expiry rarely leaves nothing.
Frequently asked questions
Can a lapsed patent be revived?
Often, within a defined window and on payment of the outstanding fee and a surcharge. Many offices also require an explanation for the failure.
What are intervening rights?
Rights acquired by someone who began using the invention in good faith while the patent was lapsed. They may continue even after reinstatement, which affects the value of reviving it.
Can an expired patent be renewed?
No. Expiry at the end of the term is final and the invention enters the public domain.
Why do patents lapse?
Almost always a missed maintenance fee, frequently because the office had an out-of-date correspondence address or the renewals docket changed hands.
What protects the product after expiry?
Trademarks and trade dress, trade secrets in the process, later filings on improvements, and regulatory exclusivities in some sectors.
This is general information, not legal advice. Laws vary by location and every situation is different — speak with a qualified lawyer about your specific circumstances.