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Patent Reissue Applications: How to Fix Errors and Strengthen Your Issued Patent

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Discovering a critical error in your issued patent can feel like watching value evaporate from your intellectual property portfolio. Your claims may be too narrow to cover competitive products you need to enforce against. Perhaps you made a priority claim error that affects your patent’s validity or limits its enforceability. Or maybe you’ve realized the inventorship is incorrect, which can render your patent invalid or create ownership issues that threaten licensing deals or litigation.

The good news is that patent errors aren’t always permanent. The USPTO provides a mechanism known as a Reissue application that allows patent owners to correct errors in issued patents, potentially salvaging valuable intellectual property rights that would otherwise be compromised or lost.

At Gallium Law, we help patent owners strategically leverage Reissue applications to strengthen patent portfolios, prepare for enforcement actions, defend against validity challenges, and correct critical defects that impact patent value. This comprehensive guide explains what Reissue applications are, when they’re appropriate, and how to use them effectively.

What Is a Patent Reissue Application?

A Reissue patent application is a special type of USPTO proceeding that allows patent owners to correct errors in issued patents. When granted, a Reissue patent replaces the original patent, incorporating corrections while maintaining the original filing date for prior art purposes.

The Legal Foundation for Reissue

35 U.S.C. § 251 authorizes Reissue applications when a patent is “wholly or partly inoperative or invalid” due to error. The error must have occurred without deceptive intent, meaning the patent owner or their representative made an honest mistake rather than deliberately attempting to mislead the USPTO.

Reissue applications may be capable of correcting much more than most patent owners realize. Beyond fixing obvious mistakes like typographical errors, Reissue applications allow for strategic claim modifications that can dramatically impact patent value and enforceability.

Broadening vs. Narrowing Reissue

Reissue applications fall into two categories with different rules and strategic implications. Broadening Reissue applications expand the scope of the claims to cover more than the original patent. This might mean removing claim elements, broadening claim language that was unnecessarily narrow, or adding new independent claims with broader scope. Broadening Reissue applications must be filed within two years of the original patent’s grant date. This strict deadline creates urgency for patent owners who realize their claims are too narrow shortly after issuance. However, once a first broadening Reissue application has been filed, so long as it was filed within the two-year window after issuance, subsequent broadening Reissue continuation applications may be filed during its pendency. 

Narrowing Reissue applications reduce claim scope to avoid prior art, correct overly broad claims, or address validity concerns. Narrowing Reissue applications have no time limit and can be filed at any point during the original patent’s life.

Six Strategic Reasons to Pursue Reissue Applications

Patent owners elect to pursue Reissue applications for various strategic reasons beyond simple error corrections. Understanding these scenarios helps you recognize when a Reissue application might benefit your patent portfolio.

Reopening a Patent Family After Issuance

Once a patent issues, the prosecution window for the respective patent family typically closes, unless there is another pending application in the patent family, or a Continuation application is filed prior to the patent being issued. If all applications in a respective patent family have been issued or are abandoned, the prosecution window is closed.

Reissue applications thereby provide a mechanism to reopen patent families after issuance. By filing a Reissue application, you create a pending application that can serve as a “parent” for new continuation applications. This allows you to pursue additional claims or continue prosecution strategies that were foreclosed when the original patent family closed.

This strategy is particularly valuable when market developments reveal claim opportunities you didn't originally pursue, or when competitive products emerge that your issued claims don't adequately cover.

Narrowing Claims to Survive an Expected Inter Partes Review

When facing the threat of Inter Partes Review (IPR), patent owners may be able to strategically narrow patent claims through a Reissue application to avoid prior art that IPR petitioners would be likely to assert. By proactively narrowing claims before an IPR is instituted, you potentially eliminate the grounds for an IPR or strengthen your position if the IPR proceeds.

Thus, rather than waiting for IPR challenges to invalidate broad claims, Reissue applications can be utilized as a defensive measure to strategically narrow claims to preserve valid,

Narrowing Claims After an IPR Decision

If the PTAB invalidates claims in an IPR proceeding, or if claims in a related family member are invalidated, Reissue applications allow you to narrow surviving claims to avoid the same prior art. This prevents future challengers from using the same invalidity arguments against related patents.

Even if your specific patent wasn't challenged in an IPR, if the PTAB invalidated claims in a family member based on prior art that also reads on your patent, proactive narrowing through Reissue applications protects against future challenges.

Modifying Claims Ahead of Expected Enforcement Actions

Before asserting patents in licensing negotiations or litigation, patent owners often identify claim modifications that would strengthen their bargaining/negotiation power or enforcement position. Reissue applications allow you to adjust claims to better cover accused products, clarify ambiguous claim language, or eliminate weaknesses that defendants would exploit.

Strategic claim modification through the use of a Reissue application can mean the difference between successful enforcement and costly litigation defeats. This requires careful due diligence, analyzing both your claims and accused products to identify optimal claim scope and the error that will serve as the ground for a reissue application.

Correcting Inventorship After Issuance

Incorrect inventorship can render patents invalid and unenforceable. Reissue applications provide a mechanism to correct inventorship errors that weren't discovered until after the patent was issued. This is particularly important when inventorship issues arise during due diligence for transactions, licensing negotiations, or litigation.

Inventorship corrections through Reissue applications require sworn declarations from the correct inventors and evidence supporting the inventorship changes. Addressing inventorship errors promptly protects patent enforceability and prevents issues from derailing business transactions.

Correcting Priority Claim Defects

Errors in priority claims can eliminate foreign priority rights or domestic benefit claims that are critical to patent validity. Common defects include incorrect application numbers in priority chains, missing or incomplete certified copies of foreign applications, or failure to claim priority to relevant earlier applications.

Reissue applications allow for correction of these defects, potentially restoring priority dates that avoid intervening prior art. For patents relying on foreign priority or complex family relationships, correcting priority defects through Reissue applications can be essential to maintaining validity.

The Two-Year Broadening Window

The most critical deadline with Reissue applications is the two-year window for filing broadening Reissue applications.

Understanding the Strict Two-Year Deadline

Broadening Reissue applications must be filed within two years of the original patent’s grant date. This deadline is absolute and cannot be extended. Missing this deadline permanently forecloses the ability to pursue a broadening Reissue application, leaving only non-broadening Reissue applications available.

Patent grant dates, also known as the “issue date,” are published on the the front page of the issued patent. To determine your broadening Reissue application filing deadline, count exactly two years from this date. Don’t wait until the deadline approaches, as preparing comprehensive Reissue applications take significant time.

Once a broadening Reissue application has been properly filed within the two-year window, additional broadening Reissue continuation applications may be filed to correct additional errors in the original patent during the first Reissue application’s pendency. Broadening Reissue continuation applications can even be filed beyond the original two-year deadline. 

What Qualifies as Broadening

Determining whether proposed claim changes constitute “broadening” requires careful analysis. Generally, any change that potentially expands the scope of protection is considered broadening. This includes removing claim elements, making claim language less specific, adding broader independent claims, or changing claim language to potentially cover more embodiments.

Even if some claims are narrowed while others are broadened, the application is treated as a broadening Reissue application subject to the two-year filing deadline. Conservative practice treats any potentially broadening change as triggering the two-year requirement.

Strategic Timing Within the Two-Year Window

While you have two years for filing a broadening Reissue application, waiting until late in the window creates risks. File broadening Reissue applications as soon as you identify any errors or other reasons, ideally within the first year after patent grant.

Early filing provides time to respond to USPTO rejections, allows coordination with other patent strategy elements, and reduces the risk of missing the deadline due to unexpected delays.

Intervening Rights and Their Impact

One of the most significant risks of Reissue applications is intervening rights, which can limit your ability to enforce Reissued claims against certain parties.

Understanding Intervening Rights

Intervening rights protect parties who relied on the original patent’s scope before a Reissue application is patented. Two types exist: absolute intervening rights and equitable intervening rights.

Absolute intervening rights apply to specific products made, purchased, or used after the original patent grant but before the Reissue patent grant. If Reissue claims cover these products but the original patent claims didn’t, the party has absolute intervening rights to continue making, using, or selling those specific products without infringement liability.

Equitable intervening rights are discretionary and courts may grant them when parties made substantial investments based on the original patent scope. These rights can extend beyond specific products to cover ongoing business activities.

Minimizing Intervening Rights Risk

Strategic claim drafting minimizes intervening rights exposure. Ensure that Reissued patent claims cover everything the original claims covered, so parties who were infringing before the Reissue patent was issued continue to infringe after. Focus broadening on aspects where no third parties have made substantial investments during the intervening period.

Consider filing Reissue applications quickly after patent grant to minimize the time window when intervening rights could accrue. The shorter the period between the original patent grant and the Reissue patent grant, the less opportunity for parties to establish intervening rights.

The Reissue Application Process

Filing and prosecuting Reissue applications involves specific requirements and procedures distinct from original patent applications.

Reissue Oath or Declaration Requirements

Every Reissue application must include an oath or declaration signed by all inventors or the assignee. This oath must state that at least one claim is wholly or partly indefective or inoperative, identify the error(s) being corrected, and declare that all errors arose without deceptive intention.

The “without deceptive intent” requirement is critical. Patent owners must honestly disclose the errors and explain how they occurred innocently. Errors that were deliberate or involved intentional misconduct will result in a rejection of a Reissue application.

Claim Presentation Requirements

Reissue applications must include all original patent claims, even if you’re only correcting some claims or adding new ones. Mark the original patented claims as unchanged, amended, or canceled using proper claim status indicators. New claims added in Reissue applications must also be clearly indicated.

This requirement ensures the USPTO and the public can easily identify what’s changing from the original patent. Failure to properly present claims can result in procedural rejections.

Examination Process

Reissue applications undergo examination similar to original applications. Examiners review claims for patentability over prior art, including art not considered during original examination. The fact that claims were previously allowed doesn’t prevent an examiner from issuing new rejections in the Reissue application process.

Examination of Reissue applications often involves heightened scrutiny, particularly for broadening Reissue applications. Examiners may question whether claimed errors truly exist and whether they occurred without deceptive intent.

Strategic Considerations for Reissue Applications

An effective Reissue application filing strategy requires balancing multiple factors while coordinating with your broader patent portfolio management.

Reissue vs. Continuation Applications

Patent owners sometimes face choices between Reissue and Continuation applications. Continuation applications require a pending parent application and allow only claims supported by the parent specification. Reissue applications can be filed after all family members have issued, but requires identifying correctable errors.

When both options are available, Continuation applications typically provide more flexibility and avoid intervening rights issues. However, a Reissue application may be your only option if the patent family has fully closed.

Coordinating Reissue with Litigation

Filing a Reissue application during active litigation creates complex strategic considerations. Courts may stay litigation (keep the lawsuit going) pending the outcome of the Reissue application, potentially delaying enforcement but allowing claim strengthening. 

Filing a Reissue application during litigation may also trigger laches and equitable estoppel concerns. Courts may view a late-filed broadening Reissue application as unfair gamesmanship, particularly if filed after the two-year window has nearly expired.

Our team’s litigation experience helps patent owners navigate these complexities and coordinate Reissue application filing strategy with enforcement objectives.

Portfolio Management Through Reissue

Sophisticated patent owners use Reissue applications as part of a comprehensive strategy for managing their IP. This might include filing Reissue applications on key patents to reopen families, using narrowing Reissue applications to strengthen validity across their patent portfolio, or correcting systematic errors that affect multiple patents.

Regular IP portfolio audits identify patents that would benefit from Reissue application filings before critical deadlines pass or enforcement opportunities are missed.

Common Reissue Pitfalls to Avoid

Several common mistakes can doom Reissue applications or create unintended consequences.

Missing the Two-Year Broadening Deadline

This is one of the most common and most devastating  mistakes when deciding to file a Reissue application. Patent owners often don’t realize they need a broadening Reissue application until competitive products emerge years after the patent grant. By then, the two-year window will have closed.

Gallium Practice Tip: Implement systems to evaluate all newly issued patents for potential broadening needs immediately after grant. Don’t assume original claims are optimal until the two-year window has safely passed.

Inadequate Error Identification

Vague or insufficient error descriptions can result in a denial or a request for a Reissue application. The oath must specifically identify the error that occurred and how it happened without deceptive intent. Generic statements indicating that claims “could be improved” do not satisfy reissue requirements. Moreover, the oath must specifically identify the Reissue application as being a broadening application and at least one independent claim to be broadened. 

Make sure to work with experienced counsel to properly characterize errors in ways that support Reissue applications while avoiding admissions that could harm enforcement or validity.

Creating New Prior Art Issues

Broadening claims through Reissue applications can inadvertently create new prior art problems. Prior art that didn’t invalidate narrow original claims might invalidate broader Reissued claims. It is a good idea to thoroughly search and analyze prior art before filing a broadening Reissue application.

This is particularly important for patents that received limited examination or where significant prior art exists that wasn’t considered during original prosecution.

How Gallium Law Can Help You With Patent Reissue

Reissue applications require specialized expertise that combines patent prosecution skills, strategic thinking, and an understanding of how a Reissue filing interacts with litigation, licensing, and portfolio management.

At Gallium Law, we provide comprehensive Reissue application services, including two-year deadline tracking, strategic timing analysis, error identification and characterization, claim drafting that achieves strategic objectives while minimizing intervening rights, Reissue application prosecution and examiner interview practice, and coordination with ongoing litigation or licensing activities.

Our team understands that Reissue applications are rarely just about correcting errors. Reissue applications are a strategic tool for strengthening patent portfolios, preparing for enforcement, and maximizing intellectual property value. We help clients identify when Reissue applications can serve their business objectives and execute Reissue filing strategies that deliver results.

Whether you’re approaching a two-year broadening deadline, facing IPR challenges, preparing for enforcement actions, or discovering errors that threaten patent value, our comprehensive services at Gallium include all aspects of patent Reissue strategy and prosecution.

Don’t Wait, Take Action Before Critical Deadlines Pass

Patent Reissue deadlines, particularly the two-year broadening window, are unforgiving. Once missed, opportunities to strengthen and correct your patents may be lost forever. Don’t let your  valuable intellectual property rights diminish because you didn’t know Reissue options existed or you waited too long to act.

If you have patents issued within the last two years, evaluate them now for potential broadening Reissue application opportunities. If you’re facing IPR challenges, litigation, or licensing negotiations, consider whether a Reissue application could strengthen your position. If you’ve discovered errors in issued patents, assess whether Reissue applications can correct them before they undermine patent value.

Be proactive and contact Gallium Law today to discuss your patent portfolio and determine w

hether Reissue applications could strengthen your intellectual property portfolio and competitive position. Time-sensitive deadlines require immediate attention, so don’t delay in exploring your options.