Five9 and Arlington Technologies Litigate Eight Contact Center Patents in Texas and California.

Two courts and eight patents

The Texas case is Arlington Technologies LLC v. Five9, Inc., No. 7:26-cv-00130 (N.D. Tex.), filed October 28, 2026. The docket shows it assigned to Judge Reed O'Connor. The California case is Five9, Inc. v. Arlington Technologies LLC, No. 3:26-cv-08048 (N.D. Cal.), filed August 3, 2026. The two complaints involve different patents, and both demand a jury.

The Texas complaint describes Arlington as a Texas limited liability company based in Allen, Texas, and Five9 as a Delaware corporation based in Pleasanton, California, and alleges that Five9 maintains a corporate office in Irving, Texas, in the district. The California complaint describes Five9 as organized under Delaware law and based in San Ramon, California, and Arlington as a Texas limited liability company based in Dallas, Texas.

How the dispute arose, according to the complaints

The Texas complaint alleges that Arlington sent Five9 correspondence on July 25, 2025 giving notice of the Asserted Patents and of the need for a license, and that claim charts for each patent were made available for download in a private data room.

The California complaint says Arlington began licensing communications with Five9 on August 18, 2025 and, on September 9, 2025, asserted that Five9 infringes the five patents named there. It says that on July 9, 2026 Arlington reasserted infringement, said it would pursue litigation absent a license, and said it had settled two pending litigations and was ready to move Five9 into its "litigation queue." Five9 says it explained in writing on July 15, 2026 why it does not infringe, and that on an August 3, 2026 videoconference Arlington maintained its position and again threatened litigation. The complaint also cites Arlington's suits against two other companies, No. 2:26-cv-00396 (E.D. Tex.) (the '819 and '517 patents) and No. 1:25-cv-00613 (D. Del.) (the '517 patent), and says those suits alleged infringement by Five9 devices, among others.

The Texas infringement case

Arlington asserts U.S. Patent 8,041,344, titled "Cooling off period prior to sending dependent on user's state," which the complaint says issued October 18, 2011; U.S. Patent 8,953,773, titled "Incorporating interactive voice response functions into a work assignment engine script," issued February 10, 2015; and U.S. Patent 9,679,567, titled "Word cloud audio navigation," issued June 13, 2017. The complaint says Arlington is the sole and exclusive owner of each patent. It accuses Five9's contact center platform, including Five9 Automated Messaging (the '344 patent), Five9 Engagement Workflow (the '773 patent), and Five9 Interaction Analytics (the '567 patent), and for each of Counts I through III it walks claim 1 through the accused features as an example. Each count alleges direct infringement under 35 U.S.C. 271(a) and, on information and belief, induced infringement and, in the alternative, contributory infringement since the July 25, 2025 notice; the complaint also alleges, on information and belief, that the infringement is willful.

U.S. Patent 8,041,344 covers methods for managing messages in a communications environment by intercepting a sender's message and either forwarding it or handling it under a delay or impaired-condition mode. Claim 1 covers intercepting the sending of a message and, when a delay mode or impaired condition mode is not active, forwarding the message to recipients, and when such a mode is active, sending after a delay, returning the message for approval, managing it based on a profile, or holding it for later management.

U.S. Patent 8,953,773 covers methods that use a work assignment engine to route contact-center work items to interactive voice response resources that gather customer information. Claim 1 covers analyzing a work item that represents a contact-center contact, determining whether customer information needed to assign the item to a non-IVR resource is present, selecting an IVR resource that can obtain a first portion of that information when it is missing, and assigning the work item to that IVR resource to execute a discrete IVR function and then automatically return the work item to the work assignment engine.

U.S. Patent 9,679,567 covers methods that record an audio or video stream, build a word cloud of selected words or phrases with frequency and stream location links, and navigate the recording from user selections in that cloud. Claim 1 covers receiving and recording an audio or video stream, identifying occurrences of selected words or phrases, generating a word cloud that shows relative frequencies and links those words or phrases to timestamps or locations in the recording, and, on user selection of a word or phrase and then of a displayed time or location, providing corresponding text at that point in the stream.

Arlington asks for a judgment of direct and indirect infringement, an accounting, damages under 35 U.S.C. 284 including up to treble damages and any appropriate royalties, pre-judgment and post-judgment interest, a finding that the case is exceptional with costs and attorneys' fees under 35 U.S.C. 285, and other relief.

The California declaratory judgment case

Five9's complaint has five counts, one for each of U.S. Patents 7,711,101, 9,715,492, 9,432,517, 8,379,819, and 7,327,834. For each, Five9 alleges, on information and belief, that Arlington owns the patent, and says it does not infringe directly or indirectly, literally or under the doctrine of equivalents, because its products do not practice at least one limitation of each claim, quoting an example limitation. The prayer asks for declarations of noninfringement of any valid claim, judgment for Five9, a finding that the case is exceptional under 35 U.S.C. 285, attorneys' fees and costs, and other relief.

The California docket shows a joint case management statement, a stipulation selecting private ADR, and a dismissal filing at entry 19, all on October 29, 2026. The entry 19 filing is not available.

What to watch next

Watch for Five9's response to the Texas complaint, further filings on the entry 19 dismissal filing in California, and any motion to transfer, stay, or dismiss in either court.