[FIRST CITIZENS BANC CORP. LETTERHEAD]

Exhibit 4.3

[FIRST CITIZENS BANC CORP. LETTERHEAD]

March 19, 2013                

Securities and Exchange Commission

100 F Street, NE

Washington, DC 20549

Re: First Citizens Banc Corp. Form 10-K for the fiscal year ended December 31, 2012

Ladies and Gentlemen:

First Citizens Banc Corp., an Ohio corporation (FCBC), is today filing an Annual Report on Form 10-K for the fiscal year ended December 31, 2012 (the Form 10-K), as executed on March 19, 2013.

Pursuant to the instructions relating to the Exhibits in Item 601(b)(4)(iii) of Regulation S-K, FCBC hereby agrees to furnish the Commission, upon request, copies of instruments and agreements defining the rights of holders of its long-term debt and of the long-term debt of its consolidated subsidiaries, which are not being filed as exhibits to the Form 10-K. None of such long-term debt exceeds 10% of the total assets of FCBC and its subsidiaries on a consolidated basis.