Have you ever noticed that after a period of deprivation, the one thing you were missing seems to come at you from all different directions? Following a great round of interviews, perhaps you’ve impressed more than one employer with your skills and personality and the offers for great jobs are now pouring in. The first step is to accept the best one. The second, perhaps more difficult, is to turn down the others.
Sure, you can just not respond to the other propositions, but it would be unprofessional and impolite. It is not only courteous to officially decline a job offer, but doing so in a graceful manner can keep you in a good light with the company, should you ever have to contact them again for any reason. But how do you do it after working so hard to prove that you’re the right one for the job?
The most important rule is to be honest. Explain why you are taking the other job over theirs in a respectful way; they may appreciate your feedback and incorporate it into the next job offer they make. In an ideal professional world, this should not be offensive to anyone, least of all the hiring manager. But if the salary is your main excuse, you may want to back it up with another reason, such as hours or location, etc.
Perhaps you know someone who would be a great fit for the position. Consider referring your friend to the company during your call as well
And yes, when in doubt, it must be a phone call.
However, if the bulk of your communication has been via email, you may choose to send a formal letter rejecting the offer. This can be a short and succinct explanation of what you would say in the phone call, explaining your reasons for declining as respectfully as possible. You do not need to cite specific examples here, you may simply say your are moving on to a position elsewhere that better serves your goals and needs. Do NOT forget to thank the hiring manager for the opportunity!
As with all professional correspondence, make sure you include the name and address of the hiring manager in the upper left corner, and check your letter for any typos or mechanical errors. You may not be working for them but you still want to look good! And lastly, decline the offer as soon as possible. It is only courteous to allow them more time to find another qualified applicant.