A patent application and a granted patent are two different things at two different stages, and conflating them is the single most common error in patent coverage. An application is a request: the applicant has filed a specification and claims and asked the U.S. Patent and Trademark Office to examine them and, if they meet the statutory bars, issue a patent. A granted patent is the end of that road — the examined, allowed document that actually confers legal rights. The distinction is not pedantry. An application gives its owner no right to stop anyone from doing anything; a granted patent does.

The publication of an application is governed by 35 U.S.C. 122. Applications start out confidential — subsection (a) provides that "applications for patents shall be kept in confidence by the Patent and Trademark Office" — and then most are published on a fixed timetable.

Subject to paragraph (2), each application for a patent shall be published, in accordance with procedures determined by the Director, promptly after the expiration of a period of 18 months from the earliest filing date for which a benefit is sought under this title. At the request of the applicant, an application may be published earlier than the end of such 18-month period.— 35 U.S.C. 122(b)(1)(A), source

That 18-month publication is what produces the flood of "Company X patents Y" headlines. But a published application is only a snapshot of what was filed and put before an examiner. The claims in it have not been examined for novelty or non-obviousness, and they routinely change — narrow, split, or disappear — during prosecution. The statute does give a published application one limited effect: under 35 U.S.C. 154(d), an applicant can obtain a "provisional right" to a reasonable royalty for certain pre-grant uses, but only after the patent actually issues and only if the infringer had notice of the published claims. Until issuance, there is nothing to enforce.

What a grant adds: the right to exclude

The grant is what changes the legal status, and the source of its power is 35 U.S.C. 154. That section is titled "Contents and term of patent; provisional rights," and it provides that every patent contains a grant "of the right to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States." The same section fixes the term: a patent generally runs from the date of grant until 20 years from the date of the earliest U.S. application to which it claims priority, subject to maintenance fees and any adjustments. So the rights and the clock both attach at grant — but the term is measured from the original filing, which is why a patent that took years to issue has a correspondingly shorter enforceable life. For the post-quantum smartcard patent US11533175B1, the application had a January 30, 2020 priority date and the patent granted December 20, 2022; the displayed term extends to early 2041, roughly 20 years from filing rather than from grant.

Telling them apart at a glance

You do not need to read the file history to know which one you are looking at — the document number encodes it. A U.S. patent application publication carries a number in the form US-YYYY-NNNNNNN-A1, where the four digits are the publication year and the kind code A1 marks it as a published application. The DigiCert source-control filing covered elsewhere on this site, US20260169731A1, is a clear example: the 2026 year, the seven-digit serial, and the A1 kind code all signal a pending application, not a granted patent. A granted patent, by contrast, has a shorter all-digit number followed by a kind code such as B1 (granted patent with no prior publication) or B2 (granted patent that was previously published as an application) — for instance US11533175B1 and the Zscaler access-control grant US10728252B2, granted July 28, 2020. The kind-code letter is the fastest reliable check: A means application, B means grant.

The 18-month timetable also has an exception worth knowing, because it explains why some inventions never appear as a published application at all. Under 35 U.S.C. 122(b)(2), an applicant who certifies that the invention has not and will not be the subject of a foreign or international application requiring publication may request that the application not be published. In that case the world sees nothing until — and unless — the patent grants. So the absence of a published application is not evidence that nothing was filed; a company can keep a filing dark and have it surface only as an issued patent years later. This is one reason application data and grant data tell different stories: the published-application stream captures most but not all of what is in the pipeline, while the grant stream captures only what survived examination. Reading a field's IP activity means watching both, and labeling each record by which stream it came from.

Three practical consequences fall out of this. First, the claims you can rely on are the granted claims, because those are the ones an examiner allowed; the claims in a published application may never issue in that form, and reading coverage off an application's claims overstates what the applicant ultimately got. Second, timing matters to scope: an application's publication date tells you when the world learned of the filing, but the priority date — discussed in the companion explainer on priority dates — is what governs the prior art an examiner can use against it. Third, a published application can still be valuable intelligence even before grant: it reveals what a company is pursuing, and it starts the clock on provisional rights once a patent eventually issues. The discipline, then, is to label every record correctly. "A new encryption patent" is premature if the document number ends in A1. It is an application — a statement of what was filed and asked, under 35 U.S.C. 122 — and only a 35 U.S.C. 154 grant turns that request into a right.