Neb. Rev. Stat. § 14-805

Upon the rejection or disallowance of any claim against a city of the metropolitan class, it shall be the duty of the city clerk to notify the claimant or the claimant's agent or attorney of such fact, unless such notice is waived in writing. Such notice may be served by any person authorized by the city clerk and must be served within ten days from the rejection of such claim. The notice and return of such notice shall be filed with the city clerk.