Neb. Rev. Stat. § 8-170

(1) Banks shall not be required to preserve or keep their records or files or copies thereof for a period longer than six years next after the first day of January of the year following the time of the making or filing of such records or files except as provided in subsection (2) of this section. (2)(a) Ledger sheets showing unpaid balances in favor of depositors of banks shall not be destroyed unless the bank has remitted such unpaid balances to the State Treasurer in accordance with the Uniform Disposition of Unclaimed Property Act. Banks shall retain a record of every such remittance for ten years following the date of such remittance. (b) Corporate records that relate to the corporation or the corporate existence of the bank shall not be destroyed. (3) All records or files or copies thereof shall be readable or legible.