dissenting.
The majority opinion concludes that the Texas Workers’ Compensation Commission’s interpretation of its own mailbox rule is unreasonable and, therefore, should not be given deference by this Court. I conclude, however, that we must defer to the TWCC’s interpretation because it is neither plainly erroneous nor inconsistent with the rule. Therefore, I dissent.
The mailbox rule at issue in this case states that a request for a review by the appeals panel is presumed to be timely filed or served if it is (1) mailed on or before the 15th day after the date of receipt of the hearing officer’s decision and (2) received by the commission or other party not later than the 20th day after the date of receipt of the hearing officer’s decision. 28 Tex. Admin. Code § 143.3(e). It is undisputed that Combined Specialty Insurance Company mailed its request for a review on or before the 15th day after it received the hearing officer’s decision. It *667is also undisputed that the mailed request was not received by the TWCC until more than 20 days after CSI received the hearing officer’s decision. CSI contends its act of faxing a copy of the request to the TWCC on the 20th day was sufficient to satisfy the second prong of the rule. When the TWCC rejected CSI’s request for review on the basis of an untimely filing, it must necessarily have concluded that the faxed copy sent on the 20th day was insufficient to meet the requirements of the rule.
The Texas Supreme Court has held that an administrative agency’s interpretation of its own regulation is entitled to deference by the courts. See Pub. Util. Comm’n of Tex. v. Gulf States Utils. Co., 809 S.W.2d 201, 207 (Tex.1991). We must give the agency’s interpretation deference unless we determine it is “plainly erroneous or inconsistent with the regulation.” See id. Our review is limited, therefore, to determining whether the TWCC has interpreted its mailbox rule in a manner that is plainly erroneous or contrary to the plain language of the rule. See id. We are not called upon to divine a better interpretation.
While the TWCC’s interpretation of its mailbox rule may be restrictive, it is neither plainly erroneous nor inconsistent with the language of the rule. The rule states that, to be timely, the request for a review must be mailed by the 15th day and received by the 20th day after receipt of the hearing officer’s decision. The TWCC’s conclusion that both requirements must be met by the same mailed document is clearly supported by the language of the rule. Under the rule as written, there is simply nothing plainly erroneous or inconsistent in concluding the document received must be the document actually mailed. Moreover, if CSI were allowed to meet the requirements of the rule by faxing a second request for review on the 20th day, the act of mailing a request by the 15th day, as required by the first prong of the rule, would become a requirement without any substantive meaning.
In a portion of its analysis, the majority cites two cases that reject the “same piece of paper” interpretation adopted by the TWCC. See Stokes v. Aberdeen Ins. Co. 917 S.W.2d 267 (Tex.1996); Williams v. Schneiber, 148 S.W.3d 581 (Tex.App.-Fort Worth 2004, no pet.). Those cases, however, address the application of the mailbox rule found in the Texas Rules of Civil Procedure to the filing of an appeal bond. The standard of review applied in the Stokes and Williams decisions was entirely different and far more deferential to the party seeking review than the one we must apply here. Rather than examining an agency’s interpretation of its own rule, the courts in those cases were charged with determining whether an “arguable interpretation” of the mailbox rule would preserve the appeal. See Williams, 148 S.W.3d at 585. Although an arguable interpretation of rule 5 of the Texas Rules of Civil Procedure would allow the deadlines for mailing and receiving a filing to be met by different copies of the same document, this does not render the TWCC’s contrary interpretation of its own mailbox rule either plainly erroneous or inconsistent with the rule.
In another portion of its analysis, the majority concedes the TWCC’s interpretation of its mailbox rule serves two of three purposes that the majority discerns underlie the rule: establishing a clear date of receipt to act as a trigger for appeals-panel action and maintaining an absolute outside deadline by which the TWCC must receive a request for review. The majority states, however, that the TWCC’s interpretation “frustrates” the other purpose of the rule that the majority describes to be *668“to give the parties the convenience of filing by mail.” It is difficult to understand how refusing to accept a document sent via facsimile for filing would frustrate the parties’ convenience of filing by mail. Regardless, what the majority fails to recognize is that the TWCC was not required to adopt a mailbox rule for the parties’ convenience. Having chosen to adopt a mailbox rule, the TWCC could limit the rule to serve the agency’s purposes. The TWCC’s interpretation does not prevent the parties from filing by mail. It simply shifts the risk of the vagaries of the postal system from the agency receiving the filing to the party making the filing. The TWCC had every right to shift the risk in this manner, and nothing in the language of the rule or the purposes behind it prevents it from applying the rule in this way.
The majority opinion’s holding that the TWCC’s interpretation of its own rule is plainly erroneous gives no deference whatsoever to the agency and is in error. Because the TWCC’s interpretation is neither plainly erroneous nor inconsistent with the language of the rule, I would affirm the trial court’s decision to grant the plea to the jurisdiction.