How does an entity amend the Montana information return?
Use Form DER-1 to amend an original tax return. Check the box at the top of the tax return indicating that this is an amended tax return. Attach the applicable forms and statements that will explain all of the adjustments in detail. Complete the entire Form DER-1 and its applicable schedules using the corrected amounts.
A. Use Form DER-1 to amend an original tax return. Indicate on the form that this represents an amended filing. Please include the applicable forms and statements that explain in detail all of the adjustments. Complete the entire Form DER-1 and its applicable schedules using the corrected amounts.