SFBC · Sound Financial Bancorp, Inc.

These shares were sold by the trustee of the CRT, and not at the direction of the reporting person, pursuant to instructions contained in the trust agreement governing the CRT, in accordance with Rule 10b5-1(c) adopted on December 10, 2025. Following the reported transaction, the reporting person continues to hold a meaningful equity interest in the Company through remaining share ownership and outstanding equity awards.

On December 10, 2025, the reporting person contributed 10,800 shares of Sound Financial Bancorp, Inc. common stock to the Stewart Charitable Remainder Trust ("CRT") for estate planning purposes, resulting in a change in form of beneficial ownership from direct to indirect. The reporting person is the sole lifetime beneficiary of the CRT and retains the right to receive distributions in accordance with the terms of the trust. An independent third-party trustee serves as the trustee of the CRT and holds sole voting and dispositive power over the shares held by the trust.

The reported transaction consists of bona fide gift to the reporting person's children undertaken in connection with the reporting person's estate, tax and retirement planning. Although the gifts represent a substantial portion of the reporting person's directly held shares, the transaction was not a sale and was effected solely for purposes of such planning. Following the reported gifts, the reporting person continues to maintain a meaningful equity interest in the Company through remaining share ownership and outstanding equity awards.

These shares were sold by the trustee of the CRT pursuant to instructions contained in the CRT, in accordance with Rule 10b5-1(c) adopted on December 10, 2025.

On December 10, 2025, the reporting person contributed 10,800 shares of Sound Financial Bancorp, Inc. common stock to the Stewart Charitable Remainder Trust ("CRT") for estate planning purposes that resulted in a change in form of beneficial ownership from direct to indirect. The reporting person is the sole lifetime beneficiary of the CRT and retains the right to receive distributions in accordance with the terms of the trust. A third-party trustee serves as the trustee of the CRT and has sole voting and dispositive power over the shares held by the trust.

Fully Exercisable.

Option is fully exercisable.

Options are fully exercisable.

Options are fully exercisable.

Options are fully exercisable.

Options are fully vested.

Reflects a gift to a donor advised fund.

Options are fully exercisable.

These shares are owned directly by Stilwell Activist Investments, L.P. ("SAI") and indirectly by Joseph Stilwell in his capacity as the managing member and owner of Value, which is the general partner of SAI. Joseph Stilwell disclaims beneficial ownership of all shares reported as owned indirectly except to the extent of his pecuniary interest therein.

Options vest in three equal annual installments beginning on January 26, 2025.

Options vest in three equal annual installments beginning on January 26, 2025.

Options vest in three equal annual installments beginning on January 26, 2025.

Options vest in three equal annual installments beginning on January 26, 2025.

Options vest in three equal annual installments beginning on January 26, 2025.

Options vest in three equal annual installments beginning on January 26, 2025.