How to decline a postdoc offer a few days after accepting it? I recently received two postdoc offers on the same day.  I accepted one (verbally, in saying &quot;I would like to accept this job offer&quot;, but I have signed nothing), but then some additional information came to light that I would not be happy in that role and the other was probably a better fit for me after all.
It is undoubtedly the case that I failed to adequately understand the pros and cons of each role before accepting one of the roles.  I accept this, but it's also my first job,  and frankly I have no idea what I am doing.  If I had a better idea what I was doing then I would have been able to extract this information before accepting one of the roles.  I accept that I have been fairly useless in this decision-making process and I am quite ashamed and horrified by it all (I'm not really sleeping and I've even had nightmares, as ridiculous as that may sound). Frankly, I just want it to end, but I want to make the right decision as it will have a profound impact on my life.  And the right decision for me is to decline the offer that I had previously accepted and go forwards with this alternative one.  At most as it stands I'll have cost them about 2-3 days of time.  It's not as if I've kept them hanging for several weeks or months before finally backing out.  I can already tell my would-be supervisor in the role I wish to decline  is a very decent and kind person and I want to cause them them the absolute minimum undue difficulties and upset.
How unethical is it to decline an offer after accepting it (but without having signed anything)?  How can I go ahead with now going back on my decision and let them know in the best possible way?  Thanks for your help.
Being on the receiving end is very unpleasant, and it will have probably cost them more than just 2-3 days; the bureaucratic arrangement, possibly losing other postdoc candidates, having to go readvertising etc. is a very serious hassle, let's not pretend it isn't. Being there, done that.
Nonetheless, you need to take a decision and inform them as quickly as possible. There is no point for you taking a postdoc that you (and ultimately them) will regret. Decide and inform. This is an unpleasantry that is part of life. Yours and theirs.
To contain the damage as much as possible, you need to face it upfront. Good luck!