Patent Marking Guide

Patent marking under 35 U.S.C. § 287(a) is the practice of placing the patent number (or a virtual marking URL) on patented products: THE CORE CONSEQUENCE OF FAILURE TO MARK: if a patent owner makes, sells, or imports a patented article WITHOUT properly marking it, damages in a subsequent infringement lawsuit are LIMITED to the period AFTER the infringer received ACTUAL NOTICE; without marking, the patent owner cannot recover damages for infringement that occurred before the infringer was notified of the patent; ACTUAL NOTICE REQUIRES: (1) the patent owner must affirmatively communicate with the infringer; (2) the communication must specifically identify the patent; (3) the communication must specifically identify the article accused of infringing; a general notification that a patent exists is NOT sufficient actual notice; WHY MARKING MATTERS FINANCIALLY: in some cases, infringement occurs for years before the patent owner files suit; without marking, all damages from that period are lost; EXAMPLE: if a patent issued in 2018, infringement began in 2019, no marking was placed on the product, and the patent owner filed suit in 2023 with a lawsuit letter as actual notice — the patent owner can only recover damages from 2023 forward, not from 2019; CONSTRUCTIVE NOTICE FROM MARKING: once articles are properly marked, ALL infringers are deemed to have constructive notice of the patent, REGARDLESS of whether they actually read the marking; this allows the patent owner to recover damages from the date infringement began; THE SIX-YEAR LOOKBACK: even with proper marking, damages are limited to 6 years before filing suit (35 U.S.C. § 286); proper marking means you can get the full 6-year lookback; improper/no marking means only from actual notice; WHO MUST MARK: the patent owner AND any licensees that make or sell the patented article; if a licensee fails to mark, the patent owner's damages can be limited even if the patent owner itself does not make products.

Physical patent marking has specific requirements about what must appear on the article: REQUIRED TEXT: the article must be marked with the word 'Patent' or the abbreviation 'Pat.' followed by the patent number; examples: 'Patent 10,123,456' or 'Pat. 10,123,456'; MARKING LOCATION: the marking must appear on the ARTICLE ITSELF; if it is not practicable to mark the article (e.g., the article is too small), the marking must appear on the PACKAGE in which the article is sold; THE PRACTICABILITY STANDARD: courts determine whether marking an article directly is 'practicable' based on the nature of the article; semiconductor chips, small components, and very small devices may qualify for package marking; WHAT CONSTITUTES A 'PATENTED ARTICLE': the article sold must itself be covered by the claims of the patent; if the patent covers a method used to make the article but not the article itself, § 287(a) marking requirements do not apply (that is the method claim exception); ACCURACY IS CRITICAL: each patent number marked on an article must actually cover that article; marking an article with a patent that does NOT cover the article (once the patent has expired, or marking the wrong patent number) constitutes FALSE MARKING; ADDING NEW PATENTS: when a new patent issues that covers an existing product, the patent owner must begin marking with the new patent number; damages for infringement of the new patent run from when the new marking begins (constructive notice); PATENT EXPIRATION: when a patent expires, the patent number must be REMOVED from the marking on new articles (selling articles marked with expired patent numbers constitutes false marking); for existing inventory, the USPTO and courts have shown some tolerance for articles already manufactured before expiration that were not yet sold; MARKING DURING PENDENCY: the phrase 'Patent Pending' or 'Pat. Pend.' may be used while a patent application is pending; 'Patent Pending' does NOT provide constructive notice for damages purposes (no issued patent), but it can put competitors on notice; FALSE PATENT PENDING MARKING: marking 'Patent Pending' when no application is pending is false marking under § 292.

Virtual patent marking was introduced by the America Invents Act (AIA) in 2011 and is now the preferred method for high-volume or frequently updated patent portfolios: STATUTORY BASIS: AIA Section 16 amended 35 U.S.C. § 287(a) to allow virtual marking; instead of marking each article with a patent number, the patent owner can mark articles with the word 'Patent' or 'Pat.' followed by a URL to a freely accessible webpage that associates the product with the applicable patent numbers; EXAMPLE VIRTUAL MARK: 'Patent: patentbrief.org/patents' — this marking on the product directs anyone who sees it to a webpage listing all applicable patent numbers for that product; WEBSITE REQUIREMENTS: (1) the website must be FREELY ACCESSIBLE — no login, no registration, no payment required; (2) the website must ASSOCIATE each product (or model number, or product family) with the specific patents that cover it; a single page listing all the company's patents without associating them with products is INSUFFICIENT; (3) the website must be KEPT CURRENT — expired patents must be removed; newly issued patents covering the product must be added promptly; ADVANTAGES OF VIRTUAL MARKING: (1) no need to change physical tooling when new patents issue or old patents expire; (2) can efficiently manage large portfolios with dozens or hundreds of patents per product; (3) updates are immediate upon website change; (4) reduces manufacturing complexity for high-volume products; DISADVANTAGES: (1) the URL must remain live and accessible throughout the entire damages period; a URL that goes down eliminates constructive notice for that period; (2) the website must be genuinely product-specific, not just a patent list; (3) recordkeeping of when products were associated with which patents is important for litigation; CONSTRUCTIVE NOTICE FROM VIRTUAL MARKING: courts have held that properly maintained virtual marking creates constructive notice in the same manner as physical marking; BEST PRACTICES: (1) use a stable, dedicated URL for the patent marking page; (2) maintain detailed records of when each product-patent association was added or removed; (3) use internet archive services to create dated snapshots proving what was on the page at specific dates.

The method claim exception is one of the most important and frequently misunderstood aspects of patent marking: THE RULE: 35 U.S.C. § 287(a) states that the marking requirement applies only to the patent owner who makes or sells 'a patented article'; the statute does NOT apply to method patents; PRACTICAL EFFECT: if a patent contains ONLY METHOD CLAIMS, the patent owner can recover damages from the date infringement BEGAN — not just from the date of actual notice; no marking is required for method-only patents; MIXED PATENT SCENARIO (both product and method claims): this is the most complex situation; the Federal Circuit has held that when a patent has BOTH product claims AND method claims, the marking requirement applies to the product claims; if the product covered by the product claims is not marked, the patent owner cannot recover pre-notice damages for the METHOD CLAIMS either in the same lawsuit; the theory is that the patent owner should not be able to circumvent the marking requirement by framing product claims as method claims; NAVIGATING MIXED PATENTS: (1) if the patent has method claims you want to enforce, consider whether to also include product claims; (2) if you include product claims, you MUST mark all products to preserve damages from the date of infringement; (3) some practitioners argue for separate patents — a product patent and a method patent — to avoid this interaction; WHAT CONSTITUTES A METHOD CLAIM: a method claim recites a series of steps performed to achieve a result; example: 'A method of forming a widget comprising: a) heating material to 500°C; b) pressing the material into a mold; ...'; method claims cover activities/processes, NOT articles; SOFTWARE METHOD CLAIMS: software patents often contain both system claims (claim an apparatus configured to perform the method) and method claims; the system claims are product claims subject to § 287 marking; the method claims are exempt; BUSINESS METHOD PATENTS: purely business method patents without any product embodiment are fully exempt from § 287 marking requirements.

False marking under 35 U.S.C. § 292 is a significant risk for companies that do not carefully manage their patent marking practices: STATUTORY BASIS: § 292 prohibits marking any article with a patent number 'for the purpose of deceiving the public' when: (1) the article is NOT covered by the marked patent; (2) the patent has EXPIRED; (3) the application identified as pending is NOT actually pending; INTENT REQUIREMENT: false marking requires INTENT TO DECEIVE THE PUBLIC — mere negligent or mistaken marking does not constitute § 292 false marking; this intent requirement is important practically; COMMON CAUSES OF FALSE MARKING: (1) EXPIRED PATENTS: marking products with patent numbers after the patents have expired; common in high-volume manufacturing where tooling is expensive to update; (2) WRONG PATENT NUMBERS: clerical errors in marking; marking a product with a patent that covers a different product or different features; (3) PATENT NUMBER CHANGES: patent numbers sometimes change (e.g., reissue patents get new numbers); (4) STALE MARKING: marking products with patents that were invalidated during reexamination or IPR; WHO CAN SUE FOR FALSE MARKING (POST-AIA): before the AIA, any member of the public could file a qui tam false marking suit and collect 50% of any fine; the AIA (2011) dramatically narrowed standing — now only a person who SUFFERED A COMPETITIVE INJURY from the false marking can sue; this eliminated the cottage industry of false marking qui tam suits that emerged around 2010; PENALTIES: up to $500 per offense (each article marked is a separate offense, but courts have discretion to set the per-article penalty at less than $500 for violations where intent is low); EXPIRED PATENT SAFE HARBOR: the AIA added § 292(c): it is not false marking to continue marking articles with an expired patent number if the articles were manufactured BEFORE the expiration date; this protects existing inventory; NEW ARTICLES manufactured after expiration must NOT be marked with the expired patent number; PRACTICAL COMPLIANCE: (1) maintain a patent marking spreadsheet or database; (2) set calendar alerts for patent expiration dates (maintenance fee deadlines: 3.5, 7.5, 11.5 years); (3) review virtual marking pages quarterly; (4) when a patent expires, update tooling orders for new inventory batches.