If you need to write a memorandum, do not worry, as it is not difficult. The basic parts of a memorandum are the heading, the message or body, the reference initials and notations, if needed. Memos are generally used within a company or office, with formal business letters being the preferred method for external communication.
To write a memorandum, keep in mind that the tone is less formal than that of a letter. The salutation (Dear…) and closing (Sincerely yours…) used in letters are not necessary in a memo. The heading area contains the name of the person(s) receiving the memorandum, the subject, the date, and the name of the sender. The older term used for the subject line was Re: which indicated “in reference to.” The format of a memo is block style paragraphs with a blank line in between.
As a rule, the sender of memo initials in ink next to his/her name in the heading. This step is more of a formality, indicating that the memo is, indeed, being sent by that person. This can be done in advance of making copies.
If someone other than the sender typed the memo, then that person’s initials are often included below the body or message of the memo. The notations area includes the word “attachment” if appropriate. When you write a memo, the term attachment is used in place of the term enclosure.
The body or message of a memo contains business-like, detailed information regarding the purpose of the memo, any action to be taken, etc. A memo should not generally address more than one topic. A memo is generally always one page or less. If the memo is to include a lot of information, bulleted lists may be beneficial.
As far as style, if you need to write a memorandum, use the active, rather than passive voice, and use active verbs. To write a memorandum, consider your audience when creating your memo. Proofread your memo carefully and take out unnecessary verbiage.