By the due date of your tax return for that year -- usually April 15.
3031 O St # 100
Lincoln, NE 68510-1512
Phone: (402) 476-9650
Fax: (402) 476-1739
105 East 6th Street
York, NE 68467
Phone: (402) 362-2004
Fax: (402) 724-5005