If a package arrives with postage due, can I just write on it return to sender or do I have to pay the $1.09???

That would be entirely your choice.  Is it a PBS package?   If you don't want to pay the additional postage, I would just put return to sender on it and then PM them (if it is a PBS sender) with the explanation as to why you returned it.

Thanks, I just wasn't sure if I HAD to pay the postage of if they would take it back if I put return to sender on it. (not a pbs package, although from a pbs person). Thanks for answering my question :)

From the Help Center:

If you receive a book postage-due that bears your current address on it (it was not forwarded), and you have accepted the package from the mail carrier already, you should contact the sender to discuss this.  Please be polite: this was probably a simple mistake.

• You should mark the book received normally, and use the mini-survey portion of the "book received" page to make a note about the postage amount due.

• The sender will get credit for sending the book automatically, but she or he should compensate you for the missing postage.

  • You can contact the sender during the process of marking the book received, or afterward using the PM button on the completed transaction for the book in your Transaction Archive
  • Be sure to note the postage-due on the "survey" portion of the Book Received page.

• You can arrange any solution that you like (the sender can give the credit back, or send you postage, or another book for no credits...whatever you agree on).

If you receive a postage-due book addressed to your previous address (if you moved since you requested it), you are responsible for the additional postage.

• Media Mail postal rate does not include forwarding (or return) service.
• You can read more about this in What if I move or change my email address?.
• If the book was mailed to you very late, this was the sender's fault.  This is the only case in which postage-due for mail forwarding from the address you provided is not the requestor's responsibility.

If you receive a book postage-due that bears your current address on it (it was not forwarded) but you have NOT accepted the package yet, you may refuse it.  It will be returned to sender.   You should contact the sender to let him or her know what happened.

• In this case, you should not mark the book received.

   

  • This is the only time that it is appropriate not to mark a book received  (i you have refused it for postage-due, and are not in possession of the book.)
  • This is the only time that it is appropriate to refuse a package from PBS (if there is postage due)

• When the book is declared "lost in the Mail" at PBS, you will get your credit back.

• You should contact the sender in this case also, to ensure that he or she is aware of the proper cost of Mailing a book.
  • You can contact the sender using the PM button on the En Route Transaction for the book on your En Route to Me tab in My Account.

If the package has proper MediaMail postage on it,  you should ask the PO why extra postage is being charged.

• This may happen if the sender does not mark the package MEDIA MAIL
• This may happen if the package contained non-Media material and it was inspected
• This may happen (rarely) if USPS makes an error and wants First Class postage for a package marked MEDIA MAIL.
• This may happen if the item has the wrong estimated weight in the database, and the sender did not correct the weight estimate when she or he printed the wrapper to send the book.

What I think happened was the person thought the weight was fine, which is was. She put 1 stamp which would of been fine, but it was thick and so I think it had to go parcel post because of this. In which case 1 stamp wasn't enough.

if it went media mail it wont neccessarily go back to the sender.  parcel post will.   in any case,  i believe that the sender will have to pay for all new postage.  a polite pm would be better IMO, that way you get the book and she can paypal you some money or mail you actual stamps.