OPINION
By certified question pursuant to Minn. R. Civ.App. P. 103.03(i), the district court asks (1) whether the filed-rate doctrine bars respondents’ action and (2) whether the primary-jurisdiction doctrine requires the district court to defer resolution of the services required by the applicable tariffs to the responsible administrative agency. Because respondents’ claim for damages, along with either specific performance or injunctive relief, amounts to an attack on tariffs filed with the appropriate regulatory entity, we answer the first certified question in the affirmative, reverse the district court’s denial of a motion to dismiss on that ground, and remand to the district court for entry of judgment. Because our answer to the first certified question is dispositive, we do not reach the second certified question.
FACTS
Appellant Northern States Power Company, d/b/a Xcel Energy (NSP), provides electrical service to customers located in Minnesota, North Dakota, and South Dakota. The relationship between NSP and its customers is regulated by tariffs authorized by the utility regulatory agencies of the three states. The tariffs set forth *753 the rates that NSP charges for services as well as the obligations of NSP and its customers to each other. All three states have identical tariffs.
In Minnesota, the legislature has established a comprehensive system for the regulation of utilities. Minn.Stat. §§ 216B.01-216B.82 (2006). Enforcement of the regulations prescribed therein is delegated to the Minnesota Public Utilities Commission (MPUC), which is charged with providing Minnesota consumers with reasonable energy rates. Minn. Stat. §§ 216B.01, 216B.08. All public utilities must file their rates, tolls, tariffs, and charges, along with all rules and contracts that will affect those rates, tolls, tariffs, and charges, with the MPUC. Minn.Stat. § 216B.05. The MPUC is charged with setting rates that are reasonable and are not prejudicial or discriminatory. Minn. Stat. § 216B.03.
On March 15, 2006, respondents Irene and David Hoffman, Jerry Ustanko, and Mulungeta Endayehu filed a complaint in district court, individually and “on behalf of all of [NSP’s] residential electric customers in Minnesota, North Dakota and South Dakota.” Respondents alleged that NSP violated its contractual obligation to maintain “points of connection” between its wires and its customers’ homes.
According to respondents, NSP initially connects a customer to its system by affixing wires to lugs within the customer’s meter box. After securing this connection, NSP installs a seal on the meter box to prevent access by the customer, a measure provided for in the tariffs. Respondents contend that over time, these connections can become corroded, loose, or both, causing a fire hazard. They argue that NSP is obligated under the tariffs to inspect and maintain its electrical wiring up through and including this connection point. The applicable tariffs provide:
The service conductors as installed by the Company from the distribution line to the point of connection with the customer’s service entrance conductors will be the Company’s property and will be maintained by the Company at its own expense.
The customer will provide for the safekeeping of the Company’s meters ....
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ALL WIRING AND EQUIPMENT ON CUSTOMER’S SIDE OF THE POINT OF CONNECTION, EXCEPT METERING EQUIPMENT, WILL BE FURNISHED, INSTALLED, AND MAINTAINED AT THE CUSTOMER’S EXPENSE....
(Emphasis added.) Respondents argue that they pay for maintenance of the points of connection through a “basic service charge” included in the monthly bill that they receive from NSP. They seek damages equal to the value of the inspections and maintenance that they claim are required and also seek either injunctive relief or specific performance requiring NSP to maintain the points of connection going forward.
On August 16, 2006, NSP moved for judgment on the pleadings, arguing that two principles of regulatory law, the filed-rate doctrine and the primary-jurisdiction doctrine, required the district court to decline jurisdiction over the case. The district court denied this motion on November 1, 2006. But on November 18, 2006, the district court certified two questions to this court: (1) whether the filed-rate doctrine bar respondents’ claims and (2) whether the primary-jurisdiction doctrine requires the court to defer resolution of the services required by the applicable tariffs to the responsible administrative agency. This certified appeal follows.
*754 ISSUES
I. Did the district court properly certify the application of the filed-rate doctrine as an important and doubtful question?
II. Does the filed-rate doctrine bar respondents’ claim?
ANALYSIS
I.
Before addressing the merits of the parties’ arguments, we must determine whether there is proper jurisdiction for this appeal. Respondents argue that the applicability of the filed-rate doctrine is not an issue that is appropriate for certification under Minn. R. Civ.App. P. 103.03(i), which allows an appeal from the denial of a motion to dismiss upon the district court’s certification of questions as “important and doubtful.”
See In re Welfare of Child of L.M.L.,
A question is important if “(1) it will have statewide impact, (2) it is likely to be reversed, (3) it will terminate lengthy proceedings, and (4) the harm inflicted on the parties by a wrong ruling by the district court is substantial.”
Jostens, Inc. v. Federated Mut. Ins. Co.,
“A question is ‘doubtful’ only if there is no controlling precedent. That the question is one of first impression is not, however, of itself sufficient to justify certification ... there [must be] substantial ground for a difference of opinion.”
Emme v. C.O.M.B., Inc.,
Whether the filed-rate doctrine bars respondents’ claim is important. The district court properly determined that certification could terminate potentially lengthy proceedings, a factor of primary importance under
Jostens. See Jostens,
The question is also doubtful. Minnesota courts have only held that one prior action was barred based on the filed-rate doctrine.
Schermer v. State Farm Fire & Cas. Co.,
Because whether the filed-rate doctrine bars respondents’ claim is an important and doubtful question, we hold that certification is appropriate under rule 103.03(i). It is therefore unnecessary to reach NSP’s argument that immediate review is also appropriate under rule 103.03(j). A certified question is a question of law, which we review de novo.
B.M.B. v. State Farm
*755
Fire & Cas. Co.,
II.
The filed-rate doctrine, as applied by the United States Supreme Court for more than a century, forbids a regulated entity from charging its customers a rate other than the one duly filed with the appropriate regulatory authority.
See H.J. Inc.,
The Minnesota Supreme Court adopted the filed-rate doctrine in
Schermer,
In so holding, the supreme court emphasized the separation-of-powers purposes underlying the filed-rate doctrine, noting that “ratemaking is a legislative function.”
Id.
at 314 (citing
Nw. Bell Tel. Co. v. State,
The holding in Schermer applies with equal force here. While Schermer arose in the context of the insurance industry, respondents do not dispute that the adoption of the filed-rate doctrine should extend to the public-utilities context. 1 Instead, respondents argue that their claims are not *756 precluded by the doctrine because they do not challenge the rates charged by NSP, but rather assert that NSP failed to provide a service — the maintenance of the points of connection — that is required by the tariff. They further assert that they do not seek a refund of the rate paid, but rather contract damages for the value of services promised but not provided.
We reject this latter distinction as no more than semantic. In determining the application of the filed-rate doctrine, our focus is on “the impact the court’s decision will have on agency procedures and rate determinations.”
H.J.,
Respondents rely on two federal decisions that they claim support the permissibility of claims that merely seek to enforce the terms of a tariff.
See Brown,
In sum, we conclude that respondents’ breach-of-contract claim against NSP is precluded by the filed-rate doctrine, as adopted and applied by the Minnesota Supreme Court in Schermer. As the agency charged by statute with approving rates, MPUC is in the best position to determine whether the point of connection must be maintained and, if so, by whom. If respondents petitioned MPUC to hold that NSP must maintain the points of connection, and MPUC concluded in respondents’ favor, it is also the entity with the power to consider the costs of such a burden, adjust the rate accordingly, and enforce that rate. See Minn.Stat. § 216B.16, subd. 5 (2006). Accordingly, respondents’ claim under Minnesota law should be dismissed.
*757
As we noted above, the application of the filed-rate doctrine to rates approved by a state agency is a matter of state law. And the question raised here does not appear to have been addressed by the North Dakota or South Dakota courts. Determining whether the filed-rate doctrine applies under these states’ laws would not only invade the province of the courts of those states to interpret their laws in the first instance, but could upset the administrative schemes designed by their legislatures to govern public utilities. Under principles of comity, we decline to resolve this issue as a matter of first impression under the law of these foreign jurisdictions.
See Reed v. Univ. of N. Dakota,
DECISION
Because we determine that (1) under Minnesota law the filed-rate doctrine applies to preclude respondents’ claim and (2) under principles of comity, the claims under North Dakota and South Dakota law should be dismissed, we reverse the district court’s denial of the motion to dismiss and remand for entry of judgment in NSP’s favor.
Certified question answered in the affirmative, reversed and remanded.
Notes
. As the supreme court recognized in
Schermer,
public utilities are a model regulated industry, in which much of the jurisprudence underlying the filed-rate doctrine has arisen.
