Business Letter vs Memorandum: Understanding Differences

Everyone · Comparison · Updated October 1, 2026 · LearnLife Editorial

What Is a Business Letter?

A business letter is a formal written message sent from one organization or individual to another outside party. It follows a specific format including the sender’s and recipient’s addresses, the date, a formal greeting, the body of the letter, a closing, and the sender’s signature or typed name. The purpose of a business letter is to communicate clearly and professionally about matters such as proposals, requests, complaints, or confirmations.

For example, a company might write a business letter to propose a partnership. This letter would start with a formal salutation like “Dear Mr. Thompson,” followed by a clear introduction of the company, the purpose of the letter, and the details of the proposal. The closing could be “Sincerely” or “Best regards,” followed by the sender’s typed name and title.

When drafting a business letter:

• Use formal language that avoids slang or contractions.
• Organize your points logically: introduction, main message, and conclusion.
• Include all relevant details without being overly wordy.
• Proofread carefully for grammar and spelling to maintain professionalism.

Business letters create a professional impression and provide a permanent record of communication, which is important when dealing with clients, vendors, or legal matters.

What Is a Memorandum?

A memorandum, or memo, is a document for communication within an organization. It is usually less formal than a business letter and designed to be brief and direct. Memos often begin with headings like “To,” “From,” “Date,” and “Subject.” The body delivers the key message clearly and quickly without lengthy introductions or formal salutations.

For instance, a department manager might send a memo like this:

To: Project Team From: Alex Johnson, Project Manager Date: [Current Date] Subject: Meeting Schedule Change

Please note that the weekly project meetings will now take place on Wednesdays at 10 a.m. instead of Thursdays. Please update your calendars accordingly.

When writing a memo:

• Use clear, concise language.
• Get straight to the point in the first sentence.
• Use bullet points or numbered lists for clarity when needed.
• Avoid unnecessary formalities or greetings.
• Include any deadlines or action items clearly.

Memos facilitate quick communication inside a company, helping teams stay informed and aligned without the need for formal letters.

How Do Business Letters and Memorandums Compare?

This table helps identify which communication method suits your needs based on audience, tone, and purpose.

Who Should Use a Business Letter?

Business letters suit professionals and organizations communicating formally with people outside their company. Examples include:

• Sales teams proposing services to potential clients.
• Customer service departments responding to complaints.
• Legal teams issuing official notices.
• Administrative staff inviting external guests to events.

To write an effective business letter:

1. Start with the recipient's full name and title.
2. Use a formal greeting, such as “Dear Mr. Smith” or “Dear Dr. Lee.”
3. Clearly state the purpose of the letter in the opening paragraph.
4. Provide necessary supporting details in the body paragraphs.
5. End with a polite closing statement, such as “Thank you for your time” or “I look forward to your reply.”
6. Use a formal closing phrase like “Sincerely” followed by your typed name and title.

For instance, instead of saying, “I want to talk about a partnership,” you might write, “I am writing to propose a strategic partnership that could benefit both our organizations.”

Formal language and complete sentences help maintain professionalism and respect in the communication.

Who Should Use a Memorandum?

Memos are best for internal communication within organizations to keep employees informed, provide instructions, or announce changes. Use memos when:

• Announcing new policies or procedures.
• Reminding staff about deadlines or meetings.
• Giving instructions for tasks or projects.
• Sharing quick updates or changes.

When preparing a memo:

• Use clear headings to identify recipients and subject.
• Write a short introduction stating the memo’s purpose.
• Use bullet points for lists such as steps to follow or key points.
• Include deadlines or action items clearly.
• Close with a note on expectations or next steps.

Example memo wording:

To: Customer Support Team From: HR Department Date: [Current Date] Subject: Updated Vacation Request Process

Effective immediately, all vacation requests must be submitted through the new online system. Please complete your requests at least two weeks before planned time off.

Using direct language and clear format ensures your message is easy to read and understand quickly by internal audiences.

What Questions Should You Ask Before Choosing?

Before deciding between a business letter and a memo, consider:

1. Who is the recipient? Are they inside or outside your organization?
2. What is the communication’s purpose? Is it formal or informal?
3. Does the message require a permanent, official record?
4. What tone is appropriate—formal or conversational?
5. How much detail is needed? Should the message be brief or comprehensive?
6. What is the preferred delivery method—postal mail, email, or intranet?

For example, if you need to notify a client about a contract update, choose a business letter. If you want to remind your team about a meeting time change, a memo works better.

Can You Switch Between Business Letters and Memorandums Later?

It’s possible to convert a memo into a business letter or vice versa, but adjustments are needed:

• To convert a memo into a business letter:
• Add formal elements like addresses, salutation, and closing.
• Expand any brief statements to include background or context.
• Use formal language and full sentences.
• Include a signature if appropriate.

• To convert a business letter into a memo:
• Remove formal addresses and greetings.
• Use memo headings (To, From, Date, Subject).
• Summarize content to essential points.
• Use a direct, clear tone.

For example, a memo summarizing an internal project update can be expanded into a business letter when sharing with an external partner by adding context and formal language.

Always consider your audience and purpose when switching formats to preserve clarity and professionalism.

How Do Business Letters Relate to Other Formal Communication?

Business letters are one of several formal communication tools, including emails and different types of letters. Business emails tend to be less formal and faster to send but may not always convey the same level of professionalism or official record as a business letter.

Understanding when to use a business letter versus an email or memo helps ensure your message is received as intended. For more on this topic, see Business Letter vs Email: When to Use Each. To understand the difference between formal and informal letters, check Formal Letter vs Informal Letter: Key Differences.

Choosing the right communication form respects your audience’s expectations and increases the chance of your message being understood and acted upon.

Frequently asked questions

Can a memo be sent to people outside the company?

Memos are generally meant for internal use only. Sending them outside may seem informal or unprofessional, so use a business letter or email for external communication.

Does every business letter require a handwritten signature?

Handwritten signatures are traditional but not always necessary, especially for electronic letters. Typed names or digital signatures are often acceptable depending on the context.

Are bullet points appropriate in business letters?

Yes, bullet points can clarify information such as lists or steps but should be used sparingly to maintain the letter’s formal tone.

How soon should recipients act on a memo?

Memos are designed for quick communication, so recipients should read and respond promptly, ideally within a day or two depending on urgency.

Can memos be posted on bulletin boards?

Yes, printed memos are often posted in common workplace areas to ensure all staff members see important announcements.

When is a business letter better than an email?

Business letters are preferred when a formal, official record is needed or when addressing recipients who expect traditional correspondence, while emails suit faster, less formal messages.