"5. On January 3, 2013, the Defendants, Nobrega's Inc. and Robert J. Nobrega, individually and as agent of the [Nobrega Nominee] Trust, and the Plaintiff, entered into an Exclusive Right to Sell Agreement (hereinafter **1010'the Agreement'), regarding the sale of the Property owned by the Trustee Defendants located at 167 Revere Beach Parkway, Chelsea, Massachusetts.
" ...
"10. Under the Exclusive Right to Sell Agreement, the Defendants, Nobrega's, Inc. and Robert J. Nobrega, individually and as Trustee of the Nobrega Nominee Trust are obligated to pay the Plaintiff a brokerage commission ( [six percent] ) upon the sale of Defendant's property during the term of the agreement."
In its answer to a counterclaim filed by the defendants, the LLC also expressly admitted the allegation that "Boston International Group, Boston International Group, Ltd., and Boston International Group, LLC, are not duly licensed as ... real estate brokers."8
b. Conducting brokering activities through unlicensed entity. The gravamen of Thomann's argument is that he performed all of the brokering activity under his individual real estate broker's license using his business name, "Boston International Group," and not through the LLC.9
*775On the evidence before it, however, the board was warranted in concluding, as it did, that Thomann had actually engaged in the business of real estate brokering through the LLC (which had no license) without first obtaining a separate license for the LLC, in violation of 254 Code Mass. Regs. §§ 2.00(11) and 3.00(14)(e). That conclusion was supported by substantial evidence.
The LLC's certificate of organization indicates that Thomann is its sole manager. The LLC's business was described in this public filing to include services related to "commercial real estate" and "any activities directly or indirectly related thereto."10 Additionally, in a draft fee agreement for the transaction in this case, Thomann had presented the LLC and himself to the client as the "Seller's Agent," and outlined the fee for services due on the sale of property. A notation on the agreement indicates that it was provided to the client. Further, when the dispute later arose, the lawsuit was commenced against the client in the LLC's name demanding payment of a real estate brokerage fee; in the same action, the LLC acknowledged that it was not licensed to engage in the real estate business. The board did not err in concluding that Thomann's conduct -- acting through the unlicensed LLC to broker the sale of the property -- violated 254 Code Mass. Regs. §§ 2.00(11) and 3.00(14)(e).
**1011c. Notice of agency disclosure.11 On appeal, Thomann also challenges the determination that he violated the agency disclosure requirements of 254 Code Mass. Regs. § 3.00(13)(a). That regulation requires real estate brokers to provide prospective purchasers and sellers of real estate with "a notice developed and approved by the board which clearly discloses the relationship of the broker or salesperson with the prospective purchaser or seller of the real estate ... at the time of the first personal meeting between the prospective purchaser or seller and the broker or salesperson for the purpose of discussing a specific property" (emphasis added). Id.
In the summary decision ruling, the hearing officer determined that there was no evidence that Thomann gave the board-approved agency disclosure notice to the seller of the property that was the subject of the marketing agreement. Although Thomann asserted -- without a supporting affidavit or other evidence -- that he had in fact provided notice, the sample agency disclosure form he claimed to have provided to his real estate clients differed in material respects from the form approved by the board. The hearing officer also found that Thomann failed to provide the form to the client at the appropriate time, i.e., in 2013, at the time the LLC entered into the marketing agreement and undertook to provide broker services, and that he failed to retain a copy of the form for the time period required by the regulations. See *776254 Code Mass. Regs. § 3.00(13)(a)(1) (three years from date of notice). There was substantial evidence in the record to support the finding of a violation in this respect.12
d. Other claims of error. On appeal, Thomann also raises assorted other claims. He contends that the board failed to reasonably accommodate his alleged disability, and otherwise violated his right to due process. He also claims that he was denied the assistance of legal counsel. While we do not address each of his claims specifically, we have reviewed each of them and find them without merit. With respect to the right to counsel, the record indicates that Thomann was in fact represented by multiple attorneys during the course of the administrative proceedings, and that he discharged his attorney after objections to the tentative decision had been filed. The record also demonstrates that Thomann was given multiple extensions of time to file materials at various stages of the proceedings. With respect to his claim of disability, there is nothing in the administrative record to suggest that Thomann requested or was denied any reasonable accommodation by the board, or that he substantiated any such claim. In sum, the record amply supports the conclusion that the proceedings before the board comported with due process requirements. See, e.g., Langlitz v. Board of Registration of Chiropractors, 396 Mass. 374, 377, 486 N.E.2d 48 (1985).
4. Sanction. Once statutory or regulatory violations have been established, the administrative agency has discretion in determining the appropriate sanction. See G. L. c. 112, §§ 61, 65A. On appeal, we consider only whether the sanction **1012imposed was a reasonable exercise of that discretion. See Sugarman v. Board of Registration in Med., 422 Mass. 338, 347-348, 662 N.E.2d 1020 (1996). See also Vaspourakan, Ltd. v. Alcoholic Beverages Control Comm'n, 401 Mass. 347, 355, 516 N.E.2d 1153 (1987). A reviewing court will not interfere with the agency's imposition of a penalty except in the most extraordinary circumstances. Id. No such circumstances are present here.
In this case, we conclude that the board reasonably exercised its discretion when it sanctioned Thomann. The $1,200 civil administrative penalty was within the range permitted by statute. See G. L. c. 112, § 61 ; G. L. c. 112, § 65A. "Given that the range of penalties is for the agency, the fact that the [board] imposed more lenient penalties for similar violations in the past does not render the sanctions against [Thomann] arbitrary or capricious." BAA Mass., Inc. v. Alcoholic Beverages Control Comm'n, 49 Mass. App. Ct. 839, 849, 733 N.E.2d 564 (2000). The ten-day suspension given to Thomann is actually less than the period imposed by the board for similar violations in other cases, and is reasonable in the circumstances of this case. With respect to the requirement that Thomann either obtain a real estate brokering license for the LLC or certify that the LLC has been dissolved, we conclude that that requirement is also reasonable, particularly in light of the business purposes articulated in the LLC's certificate of organization.
5. Conclusion. For all of these reasons, we agree with the single justice that the board's decision suspending Thomann's license for ten days, imposing a $1,200 civil penalty, and imposing certain conditions on the reinstatement of his license was *777supported by substantial evidence and free from any errors of law.
Judgment affirmed.