How to Check if a Patent Is Still in Force
A patent described as "granted" may have quietly lapsed years ago. Verify before licensing, designing around, or assuming expiry.
01
US Patents
Check at USPTO Patent Center
Go to patentcenter.uspto.gov → search by patent number. Status shows "Active" or "Expired," maintenance fee payment history, and calculated expiration date. Key maintenance fee dates: 3.5, 7.5, and 11.5 years after grant. Missing any = patent lapses (6-month grace period with surcharge).
02
European Patents
Check EPO Register + National Registers
Go to register.epo.org → search by publication number. Critical: a European patent is maintained through annual fees paid to each national office where validated. A patent may be in force in Germany but lapsed in France. Check each country separately via DPMA, INPI, UKIPO, etc.
03
Chinese Patents
Check at CNIPA
Go to english.cnipa.gov.cn or CEPIS database. Search by patent number. Annual fees required from year of grant — 6-month grace period if missed.
04
Japanese Patents
Check at J-PlatPat
Go to j-platpat.inpit.go.jp → "Legal Status" tab. Annual fees from year of registration. Detailed payment records available.
05
Multi-Jurisdiction
Use Espacenet INPADOC for All Countries at Once
The fastest method: from any patent on Espacenet → click "INPADOC legal status" tab → see events across all family members — grants, lapses, oppositions, fee payments in every jurisdiction. Also check The Lens (lens.org) for a clean aggregated view.
Espacenet INPADOCLens.orgAll Countries
⚠ Pitfalls to Avoid
Assuming "Granted" Means "Active"
A granted patent can be inactive for many reasons — expired term, unpaid maintenance fees, successful invalidity challenge, or voluntary abandonment. Always verify current status before making business decisions.
Checking Only One Country
A European patent validated in 5 countries may have lapsed in 3 of them. Each country must be checked separately. Use INPADOC for a consolidated view but verify critical jurisdictions directly.
Relying on Stale Data
Legal status databases may lag by a few months. For critical business decisions (licensing, FTO, product launch), verify directly with the relevant national patent office or through a patent attorney.