邦纳美股招股说明书(2026-06-17版)

On April30, 2026, Pacific Financial Corporation (“Pacific Financial”) and Banner Corporation (“Banner”) entered into an Agreementand Plan of Merger, which we refer to as the “merger agreement,” under which Pacific Financial will merge with and into Banner, which werefer to as the “merger.” Immediately following the completion of the merger, Bank of the Pacific, the wholly-owned subsidiary of PacificFinancial, will merge with and into Banner Bank, the wholly-owned bank subsidiary of Banner, with Banner Bank continuing as thesurviving bank (which we refer to as the “bank merger”). If the merger is consummated, each issued and outstanding share of Pacific Financial common stock (other than shares held directly byBanner or any holder of Pacific Financial common stock who properly exercises dissenters’ rights) will be converted into the right toreceive 0.2633 shares (the “exchange ratio”) of Banner common stock, with cash paid in lieu of fractional shares. A copy of the mergeragreement is attached asAppendixA to the accompanying proxy statement/prospectus and is incorporated by reference herein. Based on the number of outstanding shares of Pacific Financial common stock and Pacific Financial restricted stock unit (“RSU”)awards as ofJune12, 2026, Banner expects to issue approximately 2,654,957 shares of its common stock in the merger, excluding theadditional shares of Banner common stock that may be issued in the merger to holders of Pacific Financial stock options that properlyexercise their stock options in accordance with the merger agreement. If the merger is consummated, based on the number of issued and outstanding shares of Banner common stock and shares of PacificFinancial common stock and RSU awards on June12, 2026, we expect that Banner shareholders will own approximately 93%, and currentPacific Financial shareholders will own approximately 7%, of the outstanding shares of common stock of the combined company. Banner’s common stock is listed on the Nasdaq Global Select Market (“Nasdaq”) under the symbol “BANR.” Pacific Financial’scommon stock is quoted on the OTCQX under the symbol “PFLC.” Based on the closing price of Banner common stock as reported byNasdaq of $66.25 as of April29, 2026, the trading day immediately preceding the public announcement of the merger, the implied mergerconsideration that a Pacific Financial shareholder would be entitled to receive for each share of Pacific Financial common stock ownedwould be $17.44, with an aggregate transaction value of approximately $177million. Based on the closing price of Banner common stockas reported by Nasdaq of $67.24 as of June12, 2026, the latest practicable date before the date of the accompanying proxystatement/prospectus, the implied merger consideration that a Pacific Financial shareholder would be entitled to receive for each share ofPacific Financial common stock owned would be $17.70, with an aggregate transaction value of approximately $178.5 million.We urgeyou to obtain current market quotations of both Banner common stock and Pacific Financial common stock. We cannot consummate the merger unless we obtain the necessary regulatory approvals and unless the Pacific Financial shareholdersapprove the merger agreement. Whether or not you plan to participate in the special meeting, please take the time to vote by following thevoting instructions included in the enclosed proxy card. Submitting a proxy now will not prevent you from being able to vote electronicallyduring the special meeting. If you do not vote your shares as instructed in the enclosed proxy card, or if you do not instruct your broker howto vote any shares held for you in “street name,” the effect will be a vote against the merger agreement.Your vote is important, regardlessof the number of shares that you own. The date, time and place of the Pacific Financial special meeting are: Date:Wednesday, August12, 2026Time:10:00 a.m., Pacific TimeWebsite:www.virtualshareholdermeeting.com/PFLC2026SM The special meeting will be a virtual meeting conducted solely online via live webcast. There is no physical location for the specialmeeting.The accompanying proxy statement/prospectus contains a more complete description of the special meeting of Pacific Financial shareholders and the terms of the merger. We urge you to review this entire document carefully. You may also obtain information aboutBanner from documents that Banner has filed with the Securities and Exchange Commission (the “SEC”). Pacific Financial’s board of directors recommends that Pacific Financial’s shareholders vote “FOR” the proposal to approvethe merger agreement and “FOR” the adjournment proposal. Sincerely,/s/ Randy RognlinRandy RognlinChairman of the BoardPacific Financial Corporation Sincerely,/s/ Denise PortmannDenise PortmannPresident and Chief Executive OfficerPacific Financial Corporation You should read this entire proxy statement/prospectus carefully because it contains important information about