What to do about fee from publisher for withdrawing unpublished accepted manuscript? I had sent my manuscript mistakenly to two different journals and both journals are ready to publish (not yet published) my work which is not possible. So, after knowing their impact factor I requested one of the journals to withdraw my paper. They had just sent me the review of my paper and for withdrawal they are demanding $500 as a penalty. It is difficult for me to decide what to do.
There is wrong on every side of this situation.

First, a journal demanding money for withdrawing a paper is suspicious in the extreme. I have never in my life heard of such a practice from a legitimate journal, which means that you were probably duped into submitting to a predatory (junk) publisher.  If this is the case, you should definitely withdraw the paper and refuse to pay the money, but they may not let you: a dishonest publisher may simply publish your paper without your consent and send you a bill.  If this happens, you can try to fight it, but you may end up needing to withdraw from the other journal instead and simply write off the paper and/or the $500 as a learning experience.

And what will you have learned?


Never dual submit a paper: it is scientifically dishonest, wastes everybody's time, and seriously annoys any legitimate journal.
Never submit a paper to a journal that you haven't thoroughly investigated to determine that it is not a shady fly-by-night predatory publisher.