Patent demand letter resource

Got a letter saying you infringe?

That is irritating enough. The next step should at least be organized. Luminous Intellectual Property LLC helps companies understand what the letter says, what it leaves unanswered, and what information should be assembled for a serious review.

Annoyed is understandable. Organized is useful.

See what to gather Evaluate the letter

Important

Do not use this website as a substitute for legal advice. If your company may need legal advice, litigation strategy, privilege, or representation, involve qualified patent counsel before creating unnecessary internal commentary about the allegations.

Assertion ≠ conclusion Documents first Opinions later

01 / The letter

What makes a patent demand letter useful?

Quality is not about tone. It is about whether the communication gives the recipient enough information to identify the asserted rights, understand the accusation, and decide what requires further diligence.

Information that helps

The patent number and, when appropriate, the patent claim(s) being asserted.
The identity of the patent owner, licensee, or other party making the assertion.
The product, service, process, or activity alleged to infringe.
An explanation of why the sender believes the asserted claim reads on the accused activity.
Any claim chart, supporting exhibit, prior correspondence, or relevant deadline.
A clear statement of what the sender wants: discussion, license, cessation, payment, or another response.

Information that may be missing

No specific patent claim is identified.
The accused product or conduct is vague or undefined.
The sender's relationship to the patent owner is unclear.
The letter makes conclusions without showing the asserted claim-to-product connection.
The communication omits attachments, prior correspondence, or supporting material it references.
The requested action is unclear, open-ended, or disconnected from the information provided.

02 / What to gather

Build the file before you build the argument.

The objective is simple: collect the source material so the matter can be evaluated from the documents rather than from memory, assumptions, or hurried internal summaries.

The demand letter Keep the complete letter in the form received.

Include envelope, email headers, courier cover, or delivery details when available.

Every attachment Collect the documents, exhibits, claim charts, patent copies, links, and schedules included with the letter.

Do not assume an attachment is unimportant because it looks generic.

Patent numbers and identified claims List each patent number and note whether the sender identified particular patent claims.

Keep the sender's wording separate from your own conclusions.

Sender and asserting entity Identify the person who sent the communication, the company or law firm involved, and the stated patent owner or asserting entity.

Names, titles, email addresses, phone numbers, and mailing information can matter.

Prior communications Collect prior mail, email, courier deliveries, presentations, calls memorialized in writing, and other communications concerning the same patent or accusation.

Chronology is often easier to understand when the original communications are preserved together.

Internal routing information Identify who received the letter and who needs to know that it arrived.

For legal strategy or privilege questions, consult qualified counsel.

03 / Review framework

A structured look at the public record.

A demand-letter review can begin with the materials received and the public record surrounding the asserted patent rights. The scope of any engagement is defined separately.

A / CORRESPONDENCE

Demand materials

Organize the demand letter, attachments, asserted patents, identified claims, and prior communications.

B / PATENT

Patent record

Review the U.S. patent and the prosecution history relevant to the asserted rights.

C / ASSERTION

Asserted claims

Identify the claims the sender says matter and distinguish what the letter states from what must still be investigated.

D / STATUS

Patent & entity status

Assemble available public-record information concerning the patent and the entity making the assertion.

04 / FAQs

Common first questions.

A patent demand letter can contain a lot of conclusions and not much context. These FAQs focus on the documents, terminology, and public-record information that can help a business understand what it has received.

What is a patent demand letter?

It is a communication asserting rights under one or more patents and asking the recipient to take some action. Depending on the sender and the situation, that may mean opening a discussion, reviewing a licensing proposal, addressing an alleged use of patented technology, or responding to another stated demand.

What if the letter does not identify specific patent claims?

Record that fact. Patent claims define the boundaries of the patent rights being asserted. A useful first review separates the claims the sender actually identified from information that is absent, unclear, or must be investigated separately.

What is a claim chart?

A claim chart generally places the language of a patent claim alongside information about an accused product, process, or activity. Its usefulness depends on the quality of the information, the claim language selected, and how clearly the asserted relationship is explained. See a simple example claim chart below.

Why look at the patent prosecution history?

The prosecution history is the public record of the patent application's examination at the United States Patent and Trademark Office. It can provide context for how claims changed, what issues were raised during examination, and what became part of the issued patent record.

Why identify the patent owner and the entity sending the demand?

The company named on the letter, the person who sent it, and the recorded owner of the patent may not always be the same. Identifying the participants and their stated roles is a basic part of understanding the assertion and building an accurate record of the matter.

Why gather prior communications about the same patent?

Earlier letters, emails, presentations, attachments, and delivery records can show how the assertion developed over time. Keeping the original communications together also helps avoid reconstructing the history later from memory or incomplete summaries.

05 / Example claim chart

What a simple claim chart might look like.

This is an illustrative example only. It is not tied to any real patent, product, or legal conclusion. The point is simply to show the structure: a claim chart often lines up patent-claim language with information the sender says corresponds to the accused product or activity.

Claim element	Illustrative allegation	Example source cited by sender
Claim 1 preamble “A system for monitoring equipment performance...”	Sender alleges that the recipient's platform is a “system” used to monitor field equipment performance.	Marketing page describing the platform; product overview slide.
Element 1[a] “a sensor configured to detect operating conditions”	Sender points to installed hardware or connected devices that report temperature, vibration, or runtime data.	Product brochure; technical datasheet; user manual screenshots.
Element 1[b] “a processor configured to receive sensor data”	Sender alleges that the platform's controller or cloud service receives and processes the reported data.	Architecture diagram; API documentation; public help-center article.
Element 1[c] “a communication module configured to transmit alerts”	Sender identifies email, SMS, or dashboard alerts generated when equipment metrics cross a threshold.	Alert settings page; support documentation; feature comparison sheet.
Element 1[d] “wherein the system generates a maintenance recommendation”	Sender alleges that analytics or rules-based recommendations correspond to the claimed maintenance recommendation.	Product demo; webinar slide; case study language.

A real claim chart may be much longer, may cover multiple claims, and may rely on public materials, technical documents, screenshots, product manuals, or other sources. Some are detailed and organized; some are thin and conclusory. The value of the chart depends heavily on the quality of the analysis.

06 / About Luminous Intellectual Property LLC

Built from experience inside the patent system.

Luminous Intellectual Property LLC was founded by a duly registered United States Patent Attorney to provide information and resources about the patent system and the business of patents, informed by two decades of experience encompassing patent litigation, patent licensing, and federal technology transfer. We hope you find this information useful in your business operations.

07 / Contact

Start with the letter.

For a first contact, identify the company, the sender of the demand, the patent number if known, and the best person to contact. Do not send confidential or privileged material until you receive instructions for submitting it.

Email Luminous Intellectual Property LLC

General office fox@luminousip.com

Suggested subject Patent Demand Letter

Website LuminousIP.com