How we know when a patent dies

The corpus

13,862 US patents currently classified under CPC G06Q 40/04 (securities/commodities trading, exchanges) or G06Q 40/06 (portfolio/investment management), built from USPTO Open Data Portal bulk datasets: granted-patent core, current CPC classifications, applications, disambiguated assignees, and maintenance-fee events (vintage 2026-04-10 for the patent data, cumulative through 2026-06-30 for maintenance fees). Payment patents (G06Q 20/*) and insurance patents (G06Q 40/08) are excluded.

The term-expiry estimate

For filings on or after June 8, 1995: filing date + 20 years. For earlier filings, the later of grant date + 17 years or filing date + 20 years (the transitional rule from the GATT/TRIPS-era change to US patent term). If a filing date was unavailable, we fall back to grant date + 17 years (pre-1995 grants) or + 20 years (later grants).

Specifically, this raw estimate does not know about: patent-term adjustments (PTA) for examination delay, patent-term extensions (PTE, common for pharmaceuticals, rare in this corpus), or terminal disclaimers that can shorten a term to match a related patent. Real expiry can differ from our estimate in either direction. Always confirm against USPTO's Patent Term Calculator or Patent Center before relying on a specific date for anything consequential.

The July 2026 correction — why the countdown list is now verified

Our launch countdown list was built from the raw estimate above, and reality graded it hard: when we checked every entry against USPTO-adjusted expiration data on July 12, 2026, 29 of the 30 dates were wrong. Patent-term adjustment pushed sixteen "mid-2026 deaths" out to 2027–2030 — including our launch flagship, US8301675, which we had briefly (and wrongly) displayed as public domain; its adjusted expiration is March 2, 2029. Seven other entries had already died years earlier under terminal disclaimers or parent-anchored terms. Exactly one date survived verification as written: US7747520, August 4, 2026.

Since that correction, every date on the curated countdown pages (/dying and the homepage) is the USPTO-adjusted expiration, verified per patent against USPTO legal-status data, rather than the raw math. The searchable database (/search and /patent pages) still shows the raw estimate, clearly disclaimed — verifying 13,862 records by hand isn't feasible, which is exactly why those pages carry the disclaimer and the countdown pages carry the verification.

Status categories

Active — term has not run out and no maintenance-fee lapse is on record. Lapsed (fees) — a maintenance-fee event marked expired for nonpayment, dated before our term-expiry estimate; this takes precedence over term expiry because the fee lapse is the actual cause of death, and it usually happens years early. Expired (term) — the patent ran its full course and expired on schedule.

Why publish estimates instead of waiting for certainty

Patent status isn't published anywhere as a single live feed — it has to be computed from public filings, the way we've done here. We'd rather show our work and hedge honestly than pretend to a precision the underlying data doesn't support. Every patent detail page repeats this disclaimer for exactly that reason.