You cannot eFile an OR Tax Amendment anywhere, except mail it in. However, you can prepare it here on eFile.com.
Sign into your eFile.com account, modify your Return
and download/print OR Form 40, 40N, or 40P under My Account
Check the Amended return." on the upper left corner of the form to report that it's a tax amendment.
If you don't have an eFile.com account follow the step by step instruction on how to prepare a tax return/amendment
: If you want to do the math on your own paper return then complete, sign OR Form 40 (residents) (to be added), 40N (nonresidents) (to be added), or 40P (part-year residents) (to be added) - Print, Mail the Form to OR Department of Revenue:
Refund or No Tax Payment Amended Tax Return
PO Box 14700
Salem OR 97309-0930
Tax Payment Amended Tax Return
Oregon Department of Revenue
PO Box 14555
Salem OR 97309-0940