The Priority Chain: Provisional Applications, Foreign Filing, and the Deadlines That End Patent Rights
By Casey Scott McKay ·
A patent's priority date decides which prior art applies, whether a competitor's earlier filing blocks it, and whether foreign rights exist at all. It is set by a chain of filings and deadlines that most inventors never see. This article explains what a provisional actually preserves and what it does not, and why a thin provisional buys a date for a document rather than for an invention. It works through the twelve-month and thirty-month deadlines, why conflating them is expensive, and what a foreign filing license is. It covers absolute novelty abroad, the four filing routes and how the choice is made, and how continuation chains carry priority forward while consuming term. It closes with the practical point: this chain is built out of deadlines that arrive without notice and cannot be extended. Nearly every loss in this area is a calendar failure rather than a legal one.
IP and Technology > Patent Counseling Transactions | Article | Published 17 November 2024 - Updated 20 July 2025 | Casey Scott McKay - marksy.us
Summary. A patent's priority date decides which prior art applies, whether a competitor's earlier filing blocks it, and whether foreign rights exist at all. It is set by a chain of filings and deadlines that most inventors never see. This article explains what a provisional actually preserves and what it does not, and why a thin provisional buys a date for a document rather than for an invention. It works through the twelve-month and thirty-month deadlines, why conflating them is expensive, and what a foreign filing license is. It covers absolute novelty abroad, the four filing routes and how the choice is made, and how continuation chains carry priority forward while consuming term. It closes with the practical point: this chain is built out of deadlines that arrive without notice and cannot be extended. Nearly every loss in this area is a calendar failure rather than a legal one.
Keywords: provisional application, priority date, effective filing date, Paris Convention, PCT, national stage, foreign filing license, twelve month deadline, thirty month deadline, benefit claim, written description support, thin provisional, continuation, divisional, absolute novelty, priority chain, patent term, cross-reference, restoration of priority, filing strategy
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