Mail forwarding question -- tax papers

The Post Office will forward all first class mail unless the SENDER places an endorsement on the envelope saying "DO NOT FORWARD". In that case the Post Office will return the mail to the sender. The sender controls whether the mail gets forwarded, not the Post Office and not the addressee. If you want to make sure your forms are forwarded you need to contact the preparer of the forms and see how they handle it. A lot of companies/government offices don't want the mail forwarded. They want the forms back to "encourage" the receiver to give them the correct mailing address. I am a retired Postal employee, so unless the rules have changed in the last 10 years that is how the Post Office handles it.