How to Write a Business Proposal Letter (+ Template)

A business proposal letter is a one-page document that serves as the persuasive summary or cover letter for a comprehensive business proposal. Its goal is to briefly highlight the most important aspects of your full proposal. While not required, it’s good to use if you want to convey a higher level of professionalism, to build trust or credibility, to provide added context, or to deliver a short pitch. You can then send the letter in an email or as a physical copy.

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How Business Proposal Letters Work

A good proposal letter is formatted as a single page containing 3-4 paragraphs and fewer than 400 words, with five key elements. For formal proposal letters, first include a business heading with your contact information and your prospect’s. Then, briefly introduce your company before stating the purpose of your proposal, including the problem, solution, and key benefits. End with a strong call-to-action and a detailed signature.

Once you draft your business proposal letter, send it to your prospect along with your full proposal. You can mail a hardcopy with the letter on top and the proposal underneath, or more commonly, you can email it. If your contact is the decision maker, paste the letter into the body of an email and attach the proposal. If your contact might forward your email to others, also make the letter the first page of the proposal.

Remember that just like your full business proposal, your proposal letter should be customized for your unique prospect. It should also accurately summarize and tease your proposal, so make sure the information between the two documents are aligned and build off each other. For information on writing a full-blown proposal and how it ties into your proposal letter, read our article on how to create a business proposal.

In some cases, people use the terms “business proposal letter” and “business proposal” interchangeably. This refers specifically to a one-page business proposal. Businesses selling smaller projects or drafting a proposal to companies they have a good relationship with often use a one-page proposal containing both the letter and details.

Free Business Proposal Letter Template

We’ve created a free business proposal letter template that incorporates the crucial elements listed above, as well as examples of what to write for each. Personalize it to your specific sales situation by simply replacing the words in parentheses (aka, the fields) with your own writing. We’ll show you how to do this throughout the article, incorporating screenshots of each section.

Standard Business Proposal Letter Format

Check out each of the major components of an effective business proposal letter below, starting with business headings, continuing on with an introduction, statement of purpose, and call-to-action, and wrapping up with a strong outro.

Headings

Introduction

Statement of Purpose

Call-to-Action

Outro

Business headings provide a formal touch for your business proposal letter and include contact information for your business as well as the recipients, such as the business name, address, and points of contact. For more informal business proposal letters or proposal letters you send via email, you can consider omitting this portion of your letter.

Your introduction is an opportunity to re-introduce yourself and remind your lead, prospect, or recipient why you’re sending the associated proposal. This also gives you a chance to provide any relevant social proof to prime them before reading your full proposal, as well as tease the overall purpose.

This acts as a summary of the most important contents of your business proposal: their problem, your solution, and the benefits the prospect will receive. This gives you a chance to highlight the most important points of your proposal and accurately communicate your elevator pitch or USP for the scanning reader.

Conclude with a sentence that tells the reader what to do next. Usually, this next step will be to read your attached proposal, but it can also be to request a call or meeting to review the proposal together or to ask and answer any questions that may have arisen after reviewing. If this is the case, use concrete language with a specific ask, such as “use my Calendly link to book a time to connect this week.”

End with a polite outro stating how excited you are about the opportunity to work together. Then, sign the document if it’s a physical copy, or use a professional email signature if you’re sending it via email. Include your contact information in the signature so they can reach you.

Now that you understand the purpose of each section of the letter, follow our step-by-step instructions to write your own business proposal letter.

How to Write a Business Proposal Letter

To write a letter that effectively introduces and summarizes the proposal, draft each of the five elements in order. Below, we’ll show examples of each element from our free template. Be brief and to the point, including only the most crucial information and using clear, simple language to help the reader remain engaged. Personalize the letter so the prospect feels that you’ve listened to and truly understood their specific needs — this can inspire them to work with you over your competitors.

1. Fill Out Your Business Headings

Add business headings to the top left-hand side of your letter, listing standard information about both your business and your prospect’s. List full names, job titles, companies, addresses, and contact information, as shown below. This helps the reader know this letter is for them and which business it’s from, which can be helpful if they’re assessing multiple vendors.

Business headings template example

Some business proposals also include the date at the top, above the business headings. Some make their business information a header across the top of the page and paste their logo onto it. Do what you think looks best, and combine rows to save space if needed. This element is essentially a formality. As long as it looks organized and professional, it won’t impact the success rate of your proposal. If it looks sloppy, it might hurt it.

If you’re writing the letter in the body of an email, you can likely skip this step. Including business headers is more appropriate for letters that appear as the first page of the proposal.

2. Craft a Compelling Introduction

The introduction element is the beginning of the body of your proposal letter, starting with a greeting like “Dear” (most professional) and ending with a segue into the statement of purpose. Personalize the introduction to the prospect’s unique situation to make them feel understood; do this by beginning with background information that you’ve uncovered through conversations with them, like the agreed-upon value proposition. Keep it under 100 words, if possible.

Let’s go over the bolded fields in our template using the screenshot below. Include individual and business names, plus the following:

• First or Last Name: Whether you choose Frank or Mr. Underwood depends on your relationship with the prospect. If uncertain, it’s best to stick with the formal Mr./Mrs. Also keep in mind that they might go by other pronouns or honorifics like Mx. 
• Date of Last Conversation: The last time you spoke with them, they should have asked for a proposal or shown interest in moving into the next stage. Bring this meeting back into their memory by including the date it occurred. This makes it personal. 
• Agreed Value Proposition: At the prior meeting, you and the prospect should have agreed on the value proposition: why the prospect should choose your solution. Write it here, mirroring how they said it out loud or in their email so they remember it easily. 
• Number of Years in the Industry: Write how long you’ve been serving customers like them. This harmless brag builds your credibility as an expert. 
• Their Business Type: Business type could be “enterprise martech brands,” “freelance writers,” or “property management companies managing over 1,000 units.” Tell them that you’ve served companies just like theirs. 
• Eye-Catching Benefit: Before segueing into the statement of purpose, hook them in with another benefit of your solution. Ideally, this is one they’ve expressed excitement about in your past meetings.

Here’s how these prompts fit into our free template:

Introduction template example

3. Clearly State the Purpose of Your Proposal

Now it’s time to write the statement of purpose element of your business proposal letter. This is arguably the most critical portion of the letter, so it receives the greatest length: about 175 words. It summarizes what the prospect will learn in the attached proposal and the proposal’s purpose: to show them how you’ll help them solve a problem or achieve a goal. This element should also highlight some key benefits or your unique selling proposition (USP) to increase their curiosity.

Below are the statement of purpose fields and how to complete them: 

• Prospect’s Main Problem: This grabs their attention since it’s what they want solved. Also, include any associated costs caused by the issue. Dedicate 1-2 sentences to this. 
• Your Product or Service: Explain the solution you’re offering. In one sentence, describe what your solution is and how it works. 
• Benefits List: List the three benefits they’ll receive from your solution. This gets them excited about the proposal. Consider making benefit #3 a key differentiator (aka, a unique selling proposition) that paints you as separate from and above the competition. 
• Any Other Crucial Proposal Elements You Want to Mention: Your proposal often includes more than just the three fields above. List with commas what else they’ll find inside, whether it’s case studies or a full analysis of their situation.

We’ve included these elements in our free template using paragraphs and bullets:

Statement of purpose template example

You may be wondering if cost should get a spot in the letter. It’s generally best practice to exclude cost. There’s a reason the pricing comes at the end of the full proposal — by then, the prospect will fully understand the value you offer, which makes the cost more digestible. The only time you’d include your cost is if it were a main selling point (perhaps your cost is far below the competition’s), in which case you’d include it in the paragraph after the bulleted list.

4. Make Your Call-to-Action

Your call-to-action (CTA) is where you tell the prospect what you want them to do next. This is typically to open and read the attached business proposal. You can also ask them to call or email you when they’ve finished reading it or as questions arise, or to set up a meeting in advance so they’ll finish reading it by the time you connect again. Sometimes, it’ll be appropriate to include a contract and ask the prospect to sign it if they have no concerns.

Here are four potential CTAs to use: 

• “You can find the proposal below, attached to this email. Please give it a read, and feel free to book a meeting using my Calendly link if any questions arise or you’d like to go over the business proposal in detail.”
• “Please read the proposal below and give us a call or send us an email when you’ve finished to set up time to talk about the proposal, answer any of your questions, and discuss the possibility of working together.”
• “Please read the enclosed proposal. To make sure you have all the information you need, let’s put some time on the calendar for me to answer any questions and hear your thoughts. Are you available next week at (Three Date/Time Options)?”
• “The proposal is attached and includes all of the details we discussed on (Day). Please let me know if any questions come up. If all looks good, you can sign the contract on the final page.”

As you can see, each CTA tells the recipient to read the proposal and lays out next steps for what the prospect should do after they’ve finished reading. This tactic is effective because it solidifies next steps. We recommend going with an option that politely nudges the prospect to commit to a future meeting during which you can discuss the proposal and move the sale to a close. This accelerates the sales cycle velocity.

If you prefer a gentler approach, use the CTA in our template:

Call-to-action template example

5. End With a Friendly Outro & Signature

Your outro should be 1-2 sentences expressing confidence in your proposal while also thanking the prospect for considering you as a potential partner, supplier, or vendor. This ends the letter on a friendly note and also gives one last reason why reading the proposal will be beneficial. Below the final line of the body, sign off using “sincerely” and your full name or email signature, shown here:

Outro & signature template example

A handwritten signature adds a personal touch. If you don’t already have an esignature, you can easily include one by signing a piece of paper, taking a photo, then pasting that image into the Word, Google Docs, or PDF document of your letter.

In addition to the template we’ve given you above, it can also be helpful to review and learn from real-world examples of proposal letters.

Top 4 Business Proposal Letter Examples & Samples

Take a look at these four business proposal letter examples from around the web by scrolling left and right below. You can learn new techniques, formats, and phrasing from each of them. The more you study other businesses’ proposal letters, the better you’ll be at crafting your own.

Product Business Proposal Letter Example

RFP 360’s business proposal letter offers a good example of how to introduce a product-related proposal. The letter includes all of our recommended sections — business headings, an introduction, a statement of purpose, a call-to-action, and an outro and signature.

This letter focuses on and flatters the recipient and then talks about their company and product. While it’s ideal to build a relationship with your prospect before sending them a proposal, this letter’s first paragraph is a solid option if you haven’t had much of a chance to speak with your prospect but you want to get their guard down immediately so they’ll read the rest of the letter and open your proposal.

Marketing Agency Business Proposal Letter Example

In ClientPoint’s example, the sample company is introducing a proposal for their marketing services. The letter immediately mentions how the project will satisfy the needs of the recipient. It also uses a bulleted list to explain the main benefits of the project, so it’s easy to review.

Because the letter makes a few claims (e.g., a 30% acquisition cost reduction), the full proposal should explain how the seller arrived at each number. This is a great example, but keep in mind that it lacks two key elements: an adequate CTA and a signature. We recommend including both.

Accounting Services Business Proposal Letter Example

In this proposal letter example from All Business Templates, a business is introducing its business proposal for payroll services. Notice how it uses its logo as a border for its own portion of the business heading. The letter also properly opens with background info: a meeting they had last week and the main pain point they discussed.

The attached proposal seems to focus mainly on the costs of the service, so this letter is shorter than usual. This is okay — different selling scenarios call for different-sized letters. If you have a long-term client who wants another product delivery but doesn’t want the whole “dog and pony show,” you may just introduce the cost summary in the letter.

Web Developer Business Proposal Letter Example

Indeed’s business proposal letter is a great one to accompany a project proposal. It nails the intro and statement of purpose, spending a full paragraph describing the prospect’s main problem with their website and how they’ll fix it. You’ll notice it includes other elements like cost and a case study, which are usually found in the attached proposal. That’s because this is acting as both the letter and the proposal.

Some businesses do this to save time. If you’re pitching a current client on a product or service upgrade, they might tell you they don’t need the full proposal. Smaller businesses like freelance writers or web designers might not have the bandwidth to craft a long proposal. We have an article on a one-page proposal that goes in depth on this concept and how/when to use one.

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Oftentimes, it’s best to start with a template and then modify it to best fit your business and to incorporate ideas from examples you see online. Then, you can simply tweak your new template for each unique prospect.

Benefits of a Business Proposal Letter

A business proposal letter isn’t required when sending a full proposal. However, it has many benefits, and you should strongly consider it. Salespeople write business proposal letters for these reasons:

Build Trust

Professionalism still plays a key role in most business transactions. Prospects trust those who put in the extra effort throughout the sales process.

Hook the Prospect

The letter sparks curiosity in the reader and motivates them to read the full proposal by outlining the beneficial information they’ll find within.

Give Your Prospect Context

The letter outlines the content of the proposal, which can improve reading comprehension rates by telling the reader what to look for.

Communicate With Other Readers

Oftentimes, your business proposal will be circulated internally. If this is the case, use your letter to communicate your benefits to other readers.

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Overall, use proposal letters on a case by case basis, rather than trying a one size fits all solution. 

Bottom Line: Business Proposal Letter

Your business proposal letter is an effective lead nurturing tool and is your business proposal’s first impression. It sets the tone for what’s to come and gets the prospect excited about reading your plan to help them actualize their desires and goals. To do this effectively, it must first and foremost focus on the prospect. Accolades and rewards aside, your business must take the backseat here. Use this single page to show the prospect you know exactly how to help and get them to read on.