<p>If I were an adcom, the sooner I knew your decision the more useful it would be for me. I wouldn’t care if it were a letter or email. It would also be useful to know briefly why - “I like you, but xyz gave me full merit aid …”</p>
<p>With the acceptance letters, the colleges are going to send you a postcard or form to return if you are not planning to attend. It may have a few boxes to check for your reasons. They want to make it simple for you to communicate that you are going somewhere else. </p>
<p>Replying promptly once you know you aren’t going there is the most important thing, not the form of the reply.</p>
<p>If there’s a postcard as AmicaMom mentioned, use it. That will make their data entry much easier because it’s a part of their existing workflow. If there is no such postcard or return letter/envelop, then send an email:</p>
<p>Dear [person who signed the offer]:</p>
<p>Thank you for your offer of admission. I have decided to attend another institution.</p>
<p>If you know now you aren’t going, I would tell the colleges now. My D withdrew from some schools after being accepted to her first choice ED and her school had her send a postcard. I would either send an email or postcard to admissions of the schools you aren’t going to-- unless you have a personal connection with a person (ex. you interviewed with them) you don’t have to give them details, just say that you would like to withdraw your application and you appreciate their consideration.<br>
In some cases these emails may not get through their system and you may get an acceptance anyway, in which case you should immediately send back their reply card.</p>
<p>Agree. If you have decided or are committed, then by all means withdraw politely now. In any event, sending a letter, stating succinctly where you are going and thanking the other school for their interest, offer, whatever, is always the best. You never know when you may cross their paths again…sometimes its graduate school. And its the right thing to do, so that others can perhaps get your slot. </p>
<p>You can send the same letter to 22 schools. No harm in that. Short and sweet and say “thank you.”</p>
<p>One more comment…You should be absolutely 100% sure that you are set with a college and that you have the aid, if any, you need to make it work. If there is one iota of a doubt, don’t reply to the other colleges yet.</p>