Supplemental Jurisdiction
Supplemental jurisdiction lets the Texas Business Court hear a related claim it could not have taken on its own, but only if every party agrees and the judge permits it. Section 25A.004(f) imposes both conditions. There is no federal-style pendent jurisdiction here, and section 25A.004(h) puts several categories of claim out of reach entirely.
Federal practitioners arrive at the Texas Business Court with the wrong instinct. In federal court, supplemental jurisdiction under 28 U.S.C. § 1367 attaches by operation of law to claims forming part of the same case or controversy. The business court works nothing like that.
Two consents, not one
Tex. Gov't Code § 25A.004(f) permits the court to exercise supplemental jurisdiction over a claim related to a case within its jurisdiction, but only on the agreement of all parties to the claim and with the permission of a judge of the division before which the action is pending. Both are required. A unanimous party agreement does not bind the judge, and a willing judge cannot cure one holdout.
H.B. 40 was a substantial expansion of the business court in most respects. It did not touch this. The consent requirement survived the 2025 session intact, which is worth remembering when someone tells you the court has become broadly available.
Claims that cannot come in at all
§ 25A.004(h) operates as an absolute bar rather than a default. Medical liability claims, claims for personal injury or wrongful death, and legal malpractice claims are excluded, and H.B. 40 added claims arising out of a consumer transaction. Party agreement does not help. A judge's permission does not help. If the claim falls into one of those categories it belongs in district court, full stop.
That last addition matters to anyone drafting against a company with both commercial and retail exposure. A consumer's claim under the Deceptive Trade Practices Act cannot be dragged along behind a $20 million governance dispute.
The strategic shape of the rule
Because consent is required, supplemental jurisdiction functions as a one-party veto, and parties use it that way. A plaintiff whose case mostly fits § 25A.004(b) but includes a tag-along claim faces a choice. Seek consent and expose the request to a defendant who would rather split the case, drop the claim, or file everything in district court before a judge without a specialized commercial docket. Splitting is the worst outcome. Two proceedings on overlapping facts produce inconsistent discovery rulings and an argument about preclusion later.
The practical answer is usually to deal with the problem in the contract, before anyone is angry. Parties who anticipate business court litigation can agree in advance under § 25A.004(d)(2) that the court has jurisdiction over disputes arising from the transaction, and they can draft the scope broadly enough that fewer claims need supplemental treatment at all. Consent given in a signed agreement is far easier to enforce than consent requested from an adversary in the middle of a fight.
When you do have to ask, ask early and ask in writing. A request made after the pleadings have hardened reads as a tactical move. A request made with the removal papers reads as case management.