Willfulness and Enhanced Damages Checklist: A Practical Checklist

Summary. This checklist turns the law of willful patent infringement and enhanced damages into check-off tasks for both sides of a dispute. Phase 1 covers the accused infringer's first two weeks after a notice letter, Phase 2 the analysis, opinion, design-around, and Patent Office decisions that build a good-faith record, and Phase 3 the patent owner's tasks before and when sending a letter. Phases 4 through 6 cover litigation: pleading and motions to dismiss, discovery and the advice-of-counsel election, and trial and post-trial practice, including the Read factor briefing and exceptional-case fees. Each item links the governing authority and adds a short practical note where useful. Red-flag boxes, a deadlines table, a short worked example, and a list of common failure points close the checklist.

How to use this checklist

Willfulness disputes are won or lost on records made long before trial. This checklist is organized by phase so that each side can see what it should be doing at each point and what the other side is likely doing. Phases 1 and 2 are for the company that received a letter (the "recipient" or, once sued, the "defendant"). Phase 3 is for the patent owner. Phases 4 through 6 apply to both sides once a lawsuit is filed, with items marked [P] for patentee, [D] for defendant, or [Both].

Three rules sit behind every item:

1. Enhancement under 35 U.S.C. § 284 is discretionary and reserved for egregious conduct, measured by what the infringer knew when it acted, Halo Electronics, Inc. v. Pulse Electronics, Inc., 579 U.S. 93 (2016).
2. Willfulness, for the jury, means "no more than deliberate or intentional infringement," Eko Brands, LLC v. Adrian Rivera Maynez Enterprises, Inc., 946 F.3d 1367 (Fed. Cir. 2020); the degree of enhancement is for the judge.
3. The absence of an opinion of counsel cannot be used to prove willfulness or inducement intent, 35 U.S.C. § 298.

For the doctrine, read Willful Patent Infringement and Enhanced Damages After Halo: Knowledge, Opinions of Counsel, and Section 298. For the narrative version of Phases 1 and 2, read Managing Willfulness Risk After a Patent Notice Letter: A Practical Guide. Forms for many items are in the Willfulness Toolkit: Notice Letter Responses, Opinion of Counsel Engagements, and Read Factor Analyses.

Phase 1: The recipient's first two weeks

Intake (Days 0 to 2)

• Log receipt. Record the date, method of delivery, addressee, and every person who has seen the letter. Note: the receipt date is likely the start of the willfulness period and, for an unmarked patentee, of the damages period under 35 U.S.C. § 287(a).
• Route to counsel the same day. One person forwards the letter to in-house or outside counsel; no one else circulates it.
• Send a communications instruction. Counsel tells everyone who saw the letter not to discuss the patents in email, chat, or meetings except at counsel's request. Note: privilege attaches to communications made to obtain legal advice, Upjohn Co. v. United States, 449 U.S. 383 (1981); casual business chatter is not protected.
• Do not adopt a "do not look" policy. Channel knowledge to counsel instead. Note: deliberate avoidance of knowledge can be willful blindness, Global-Tech Appliances, Inc. v. SEB S.A., 563 U.S. 754 (2011).
• Identify the sender. Operating competitor, patent assertion entity, university, or individual. Check its litigation history.
• Pull each patent and its file history. Confirm issue date, expiration, maintenance fees, recorded assignee under 35 U.S.C. § 261, pending continuations, and prior PTAB or reexamination proceedings.
• Identify the accused products and their revenue over the six-year window of 35 U.S.C. § 286 and the forecast period.
• Check the patentee's marking. If it sells unmarked products, pre-notice damages are unavailable. Note: actual notice requires "a specific charge of infringement by a specific accused product or device," Amsted Industries Inc. v. Buckeye Steel Castings Co., 24 F.3d 178 (Fed. Cir. 1994), from the patentee, Lans v. Digital Equipment Corp., 252 F.3d 1320 (Fed. Cir. 2001).
• Calendar the letter's deadline and an internal decision date a few days earlier.

Red flag: the first email. If the first internal reaction to the letter is already in writing ("we probably infringe," "ignore until they sue"), tell counsel now. It cannot be deleted (and must not be, once a hold applies), but counsel can plan around it, and the company's later conduct can show that the reaction did not reflect its considered position.

Preservation (Days 2 to 7)

• Decide whether litigation is reasonably anticipated. For a specific letter, assume yes.
• Issue a written litigation hold to engineering, product, sales, and leadership custodians, covering design files, source code, change orders, test data, sales data, and communications about the patentee. Note: loss of electronically stored information after the duty attaches can lead to sanctions under Fed. R. Civ. P. 37(e). See Litigation Hold and Evidence Preservation Checklist: A Practical Checklist.
• Suspend auto-deletion for the relevant chat channels, email accounts, and repositories.
• Collect acknowledgments from each custodian and calendar a reminder at 90 days.
• Preserve prior clearance work. Earlier freedom-to-operate analyses may become central evidence of good faith or of knowledge. See Freedom-to-Operate Search: A Practical Checklist.

Strategic assessment (Days 3 to 14)

• Assess declaratory judgment jurisdiction. A specific assertion against identified products usually suffices, MedImmune, Inc. v. Genentech, Inc., 549 U.S. 118 (2007); SanDisk Corp. v. STMicroelectronics, Inc., 480 F.3d 1372 (Fed. Cir. 2007); Hewlett-Packard Co. v. Acceleron LLC, 587 F.3d 1358 (Fed. Cir. 2009).
• Decide whether to file first under 28 U.S.C. § 2201, considering forum, cost, and whether the dispute might end without suit.
• Protect the IPR option. Do not file a declaratory judgment claim of invalidity before an IPR petition. Note: such a filing bars the petition, 35 U.S.C. § 315(a)(1); a counterclaim does not.
• Send an acknowledgment within the letter's deadline, asking for the full list of asserted claims, the infringement theory for each product, and licensing terms. Make no product statements and no admissions.
• Notify insurers under every potentially responsive policy, in writing, and keep proof of notice.
• Review indemnity obligations and rights in customer and supplier contracts, and the UCC § 2-312(3) warranty against infringement where goods are sold by a merchant.

Phase 2: Building the good-faith record (Weeks 2 to 26)

Privileged analysis

• Engage patent counsel for a privileged preliminary assessment of infringement, validity, and exposure.
• Provide real product facts. Schematics, code, and specifications, not marketing summaries. Note: an opinion based on incomplete facts can support enhancement, as in nCube Corp. v. SeaChange International, Inc., 436 F.3d 1317 (Fed. Cir. 2006).
• Request engineering input in writing from counsel, stating that it is for the purpose of legal advice.
• Analyze all likely claims, not only the charted claim, including dependent claims and pending continuations.
• Consider every invalidity ground, including 35 U.S.C. § 101, § 102, § 103, and § 112. Note: in court, invalidity requires clear and convincing evidence, Microsoft Corp. v. i4i Ltd. Partnership, 564 U.S. 91 (2011).
• Estimate exposure with and without enhancement, so leadership sees how much risk is driven by future conduct.

The opinion decision

• Decide whether to commission a formal opinion for reliance, keep advice informal, or both. Note: there is no duty to obtain one, In re Seagate Technology, LLC, 497 F.3d 1360 (Fed. Cir. 2007) (en banc), and no adverse inference from keeping advice privileged, Knorr-Bremse Systeme Fuer Nutzfahrzeuge GmbH v. Dana Corp., 383 F.3d 1337 (Fed. Cir. 2004) (en banc).
• If commissioning one, use counsel separate from likely trial counsel. Note: reliance on opinion counsel ordinarily does not waive trial counsel's privilege, Seagate, 497 F.3d 1360.
• Define the scope in the engagement letter: patents, claims, products and versions, materials to be reviewed, and the assumption that facts provided are complete.
• Obtain the opinion promptly. An opinion obtained years after notice did not prevent trebling in Arctic Cat Inc. v. Bombardier Recreational Products Inc., 876 F.3d 1350 (Fed. Cir. 2017).
• Require competence markers: claim-by-claim analysis, claim construction, product comparison, doctrine of equivalents, prosecution history, prior art applied under the correct burden. Note: the test is whether it would instill a reasonable belief that a court might hold the patent invalid, not infringed, or unenforceable, Ortho Pharmaceutical Corp. v. Smith, 959 F.2d 936 (Fed. Cir. 1992).
• Address noninfringement, not only invalidity, if inducement is a risk. Note: belief in invalidity is no defense to inducement, Commil USA, LLC v. Cisco Systems, Inc., 575 U.S. 632 (2015).
• Store the opinion separately from informal advice and trial materials, to keep the waiver map clean.
• Do not disclose the advice's conclusion to customers, investors, or the patentee unless you have decided to rely on it.

Red flag: the curated opinion. If anyone suggests withholding a document or fact from opinion counsel "to get a cleaner opinion," stop. Global-Tech (a right-to-use study commissioned without telling counsel the product was a copy) and nCube show how that choice becomes the patentee's best evidence.

Design-around

• Ask engineering for alternatives that avoid the specific claim limitations counsel identifies.
• Have counsel review the chosen alternative against the patent and any pending continuation claims before release.
• Document the change in business records: engineering change order, date, products affected, and a neutral statement of purpose ("to reduce IP risk"). Note: designing around is legitimate and encouraged, State Industries, Inc. v. A.O. Smith Corp., 751 F.2d 1226 (Fed. Cir. 1985), and weighs against enhancement, Westvaco Corp. v. International Paper Co., 991 F.2d 735 (Fed. Cir. 1993).
• Decide what happens to old-design inventory and record the decision and dates.
• Avoid admissions in design records ("the old version infringes").

Patent Office challenge

• Evaluate IPR, PGR, and ex parte reexamination, 35 U.S.C. § 311, § 321, § 302.
• Assess discretionary-denial risk under 35 U.S.C. § 314(a). Note: USPTO institution practice changed substantially in 2025, with discretionary-denial decisions moved to the Director level; check the current Director guidance and rules before forecasting.
• Weigh estoppel under § 315(e)(2) before choosing grounds.
• File promptly if filing. A petition filed soon after notice documents a contemporaneous belief; one filed late says less.

Customers and ongoing monitoring

• Coordinate customer communications through counsel, and put any common-interest arrangement in writing before sharing analysis.
• Review customer-facing instructions and support materials for inducement risk under 35 U.S.C. § 271(b).
• Calendar quarterly reviews of the patent family, product changes, and the patentee's other litigation.
• Re-run the analysis whenever the product changes or new claims issue.

Phase 3: The patent owner before and when sending a letter

• Confirm title and standing. Recorded assignments, any licenses that limit enforcement, and the correct sender. See Patent Ownership, Assignments, and Standing: Chain-of-Title Problems That Sink Cases.
• Audit your own marking, including licensees' products. Note: the patentee bears the burden to prove compliance, but the accused infringer must first identify unmarked products, Arctic Cat, 876 F.3d 1350; stopping unmarked sales does not revive pre-notice damages, Arctic Cat Inc. v. Bombardier Recreational Products Inc., 950 F.3d 860 (Fed. Cir. 2020). See Patent Marking Compliance: A Practical Checklist.
• Build a pre-suit infringement analysis that would satisfy Fed. R. Civ. P. 11(b).
• Name the patent, at least one claim, and the accused product by model in the letter; attach a claim chart if willfulness matters.
• Address it to someone with authority and use trackable delivery.
• Decide whether you are ready to sue if the recipient files a declaratory judgment action first.
• Check state bad-faith demand-letter statutes for required content and prohibited statements.
• Issue your own litigation hold once enforcement is contemplated.
• Keep proof of delivery and any acknowledgment; these become exhibits on knowledge.

Red flag: the blanket letter. A letter to an industry that lists patents without charging a specific product may not satisfy § 287 notice under Amsted and gives a weak foundation for willfulness pleading. If damages or willfulness matter, be specific.

Phase 4: Pleading and the motion to dismiss

• [P] Plead knowledge with facts: date and content of the letter, recipient, prior dealings, and continued conduct. Note: plausibility is required under Fed. R. Civ. P. 8, Bell Atlantic Corp. v. Twombly, 550 U.S. 544 (2007), and Ashcroft v. Iqbal, 556 U.S. 662 (2009).
• [P] Plead the knowledge prerequisite for each patent. Note: knowledge "continues to be a prerequisite to enhanced damages," WBIP, LLC v. Kohler Co., 829 F.3d 1317 (Fed. Cir. 2016).
• [P] Separate pre-suit and post-suit theories, and know your district's view on whether the complaint itself can supply knowledge, ZapFraud, Inc. v. Barracuda Networks, Inc., 528 F. Supp. 3d 247 (D. Del. 2021).
• [D] Move to dismiss conclusory willfulness allegations under Fed. R. Civ. P. 12(b)(6), particularly "information and belief" knowledge allegations.
• [D] Calendar the IPR deadline: one year from service of the complaint, 35 U.S.C. § 315(b).
• [P] If dismissed, plan an amendment after discovery. See Amended Pleading and Relation Back Checklist: A Practical Checklist.

Phase 5: Discovery

• [Both] Negotiate the advice-of-counsel election date in the scheduling order under Fed. R. Civ. P. 16, early enough to depose opinion counsel.
• [D] Build a privilege waiver map before electing. List every communication with every counsel about the patent and product, and sort it under the three In re EchoStar Communications Corp., 448 F.3d 1294 (Fed. Cir. 2006) categories; check the reach of Fed. R. Evid. 502(a).
• [D] Prepare opinion counsel as a fact witness if relying.
• [P] Request the willfulness record: routing of the letter, engineering analyses, design-change records, board or leadership materials, and communications about the patentee, under Fed. R. Civ. P. 26(b)(1).
• [P] Serve a 30(b)(6) topic on the defendant's knowledge of the patent and response to it, Fed. R. Civ. P. 30(b)(6).
• [D] Log withheld documents consistently. See Preparing a Privilege Log: A Practical Checklist.
• [Both] Gather Read factor evidence: size and finances, duration of post-notice sales, remedial steps, copying evidence, and litigation conduct, per Read Corp. v. Portec, Inc., 970 F.2d 816 (Fed. Cir. 1992).

Red flag: the late election. A defendant that announces reliance on advice after fact discovery closes may be barred from using it, and one that waits until trial to decide has usually already shaped its witness testimony around privilege. Decide on the court's schedule.

Phase 6: Trial and post-trial

Pretrial

• [D] Consider moving to bifurcate willfulness under Fed. R. Civ. P. 42(b).
• [D] Move in limine to bar argument that the absence of an opinion proves willfulness (§ 298), and to address PTAB evidence under Fed. R. Evid. 403. See Motion in Limine Checklist: A Practical Checklist.
• [Both] Propose willfulness instructions under Fed. R. Civ. P. 51. Note: patentees cite Eko and SRI International, Inc. v. Cisco Systems, Inc., 14 F.4th 1323 (Fed. Cir. 2021), against "wanton" or "malicious" in the definition; defendants cite Bayer HealthCare LLC v. Baxalta Inc., 989 F.3d 964 (Fed. Cir. 2021) for the point that knowledge plus infringement is not enough. Check the current Federal Circuit Bar Association and AIPLA model instructions.
• [Both] Draft the verdict form under Fed. R. Civ. P. 49 with willfulness questions by patent and, if notice dates differ, by period.

Post-trial

• [Both] Preserve and brief JMOL under Fed. R. Civ. P. 50; a Rule 50(b) motion must follow a Rule 50(a) motion made before submission.
• [Both] Brief enhancement factor by factor under Read, citing record evidence. Note: appellate courts defer to a reasoned explanation and remand an unexplained one, as in Polara Engineering, Inc. v. Campbell Co., 894 F.3d 1339 (Fed. Cir. 2018).
• [Both] Calibrate the multiple. Affirmed results range from modest enhancements, such as roughly 65 percent in Georgetown Rail Equipment Co. v. Holland L.P., 867 F.3d 1229 (Fed. Cir. 2017), to trebling in Arctic Cat.
• [P] Move for fees under 35 U.S.C. § 285 where the case stands out under Octane Fitness, LLC v. ICON Health & Fitness, Inc., 572 U.S. 545 (2014). See Attorney Fee Petition and Bill of Costs Checklist: A Practical Checklist.
• [Both] Frame the appeal knowing the standards: substantial evidence for the willfulness verdict, abuse of discretion for enhancement and fees, Highmark Inc. v. Allcare Health Management System, Inc., 572 U.S. 559 (2014).

Deadlines and timing table

Short worked example

Calder Pumps receives a letter from Ostrander Fluidics identifying a patent on a variable-speed impeller control, claim 7, and Calder's VX line. Calder's controller (Phase 1) logs receipt, routes the letter to counsel, and stops a reply-all thread that had already begun. A hold issues on Day 4. Counsel concludes Ostrander, a competitor that marks its pumps, could seek an injunction, and that Calder has declaratory judgment standing. Calder sends an acknowledgment on Day 12.

In Phase 2, the privileged review finds claim 7 likely infringed but vulnerable to an obviousness challenge. Calder commissions a formal invalidity and noninfringement opinion from a firm it will not use for trial, files an IPR petition in month 3, and ships a redesigned controller in month 5 with a documented engineering change order. Ostrander sues in month 6. At trial in year 3, the jury finds infringement by the old controller for the five months before the redesign and finds the infringement not willful. The opinion, the IPR, and the redesign were all before the jury or the court, and no internal message contradicted them.

Common failure points

• The first internal reaction to the letter is written casually and becomes Exhibit 1.
• The hold issues months after the letter, and chat history is gone.
• The opinion is obtained after suit, or from trial counsel, or on incomplete facts.
• An invalidity declaratory judgment action is filed before the IPR, forfeiting the petition.
• Engineers record legal conclusions in design documents.
• The defendant tells customers that "counsel says we are fine," creating a waiver argument without the benefit of reliance.
• The patentee's letter is vague, so it supports neither § 287 notice nor a strong willfulness pleading.
• Neither side builds a Read factor record before trial, leaving enhancement to a thin post-trial submission.

This checklist is general information, not legal advice for any particular situation. Local patent rules, model instructions, and Patent Office practice vary and change; confirm current requirements.

Related Documents

Related Articles

• Willful Patent Infringement and Enhanced Damages After Halo: Knowledge, Opinions of Counsel, and Section 298: the doctrine behind each item.
• Patent Damages: Reasonable Royalties, Lost Profits, Apportionment, and Enhancement: the base award that enhancement multiplies.
• Litigation Holds, Spoliation, and Rule 37(e): Preserving Electronic Evidence Before It Costs You the Case: the sanctions risk behind Phase 1.

Related Guides

• Managing Willfulness Risk After a Patent Notice Letter: A Practical Guide: the narrative version of Phases 1 and 2.
• Filing or Defending a Declaratory Judgment Action: A Practical Guide: if you decide to file first.
• Filing or Defending an Inter Partes Review: A Practical Guide: the Patent Office route.

Related Checklists

• Patent Damages Checklist: A Practical Checklist: the compensatory case.
• Patent Marking Compliance: A Practical Checklist: preserving pre-notice damages.
• Litigation Hold and Evidence Preservation Checklist: A Practical Checklist: the hold itself.
• Indirect Patent Infringement Claim Checklist: A Practical Checklist: inducement intent alongside willfulness.

Related Toolkits

• Willfulness Toolkit: Notice Letter Responses, Opinion of Counsel Engagements, and Read Factor Analyses: forms for the items in this checklist.
• Indirect Infringement Toolkit: Knowledge Evidence, Direction or Control Proof, and Substantial Noninfringing Use Analyses: knowledge evidence templates.
• Patent Litigation Toolkit: A Roadmap and Research Guide: the broader litigation roadmap.