A requisition letter is a medium for expressing the need or wish for a favor from an individual or a company. It is considered a formal letter, and therefore, you need to pay particular attention to its structure and spelling and grammar. You also need to use persuasive language, as it is supposed to convince the person you are addressing to do something for you they may not have previously considered.

Introduce yourself in the first paragraph and state the reason you are writing the letter. Write in a polite manner while still being direct about your reason for writing. If you were referred by someone, include his name in this paragraph. If necessary, remind the recipient how he knows you by reviewing, briefly, some of the high points of your relationship.

Explain your request in the second paragraph and back up your explanations with details about the request. Say directly what you wish him to do for you by adopting a polite tone while making your request. Show the recipient how he will benefit by considering your request.

Explain your background briefly and underscore the situation for which you need assistance from the recipient by presenting the detailed information required to help the person you are writing to make a decision. Mention that you will make a follow up with a phone call.

Add your email address or telephone number in the body of the letter. However, this may be optional if you have already included them in your return address at the introduction. Invite the recipient to contact you in case there is something she may not have understood regarding your request. Conclude the body of your letter by thanking the reader for his anticipated assistance and consideration.

Close the letter formally, using "sincerely" followed by your name and your title. Print the letter on plain white paper and sign your name below your title. Fold the letter to fit into a business-sized envelope, print the address of your recipient on the envelope and mail it to the recipient.