Writing a Proposal Letter to Offer Services [Free Samples]

A proposal letter to offer services is a sales document that is sent by a business to a prospective client. It is primarily used to solicit the client’s business and focuses on how the service being offered by the business will benefit the client. 

There are two main types of business proposal letters. If the business proposal is being sent because of a request for proposal (RFP), the letter should follow the structure that is requested in the RFP.

The most common features are:

  1. A short description of the business’s service or product and how they will benefit the client’s business
  2. A short description of the project and how the business will handle it
  3. Answers to any questions put by the RFP
  4. A quote for materials, tools, delivery, labor and other costs of the project

One type is sent when the services or products are requested by the client, and the other is sent to a prospective client unsolicited. 

The letter is focused on a specific project and not intended as a general sales document. They are sent to the specific person in charge of the project, and the aim is to develop a business opportunity.

First Step

The first step a business should take before sending an unsolicited business proposal letter is to learn as much as possible about the potential client. 

This will not only impress the client, it will also help the business avoid becoming connected to a less-than-standard client. The business can research the client’s mission statement, and how they make decisions.

This will help the business frame its letter. For example, most companies want more profit, but if the company is looking for something new to offer their clients, this may be the angle to take, or if the client needs an edge on their competition, this can be mentioned in the letter as a benefit. 

Potential Client

If the letter is being sent to a potential client unsolicited, its intent is to create interest in the client for the business’s products or services creating a new business opportunity. 

It should follow the same format as an RFP but include more information that will answer any questions the client may have. The aim is to present a valuable proposition with a call to action.

Unsolicited Letter

An unsolicited letter needs to catch the client’s attention. One of the best ways to do this is to present an offer that they won’t want to refuse. 

Once this offer is on the table, the letter needs to make it easy for the client to accept. If the proposal is very complicated, the client will most likely disregard it.

The proposal should be simple, which means the business may need to take on more responsibility at first. Once the prospective client becomes a real client, the collaboration will become more lucrative. 

The letter should also be specific. It’s not enough to tell the potential client their profits will increase, the business needs to give specific numbers based on predictions from their own marketing statistics that show real data. Along with specific numbers, the letter needs to be personal. 

A letter that appears to be from a template or generic will not be taken seriously.  It will look like an advertisement and be discarded. If the letter is from a specific person to a specific person, it will be valued.

Call To Action

A call to action at the end of the letter is essential, but it shouldn’t be overbearing, unrealistic or inaccurate. 

For example, the offer may expire after 10 days, or be for an unspecified limited time only. If the letter offers any incentive, it must be true. 

Here are examples of an unsolicited service proposal letter. It should be written in the format of a formal business letter and mailed by certified mail. 

Emails are far too easy to dismiss or delete. A certified letter will be treated with more respect.

sample 1 - Proposal Letter To Offer Painting Services

Steve Jordan
Jordan Painting Company
124 Copper Street
Philadelphia, PA, 19145

May 23, 2021

ABC Apartment Complex
123 Apartment Road
Philadelphia, PA, 19145

RE: Apartment Complex Painting Services

Dear Name of Manager:

This letter is to propose painting services for the ABC Apartment Complex in a formal manner. 

We have successfully maintained painting services in more than 10 apartment complexes in Philadelphia for the past 25 years, and we would be pleased to supply customer testimonials.

When compared to calling a painter every time there is a problem, a painting maintenance contract from us can save you a lot of money. It also relieves you of the burden of obligation. 

On labor, we offer a 90-day warranty. I’ve attached a copy of the standard contract, which includes a cost estimate. It can, however, be customized to match your individual needs.

I’d be delighted to discuss our services with you and answer any queries you may have. I may be reached at [steve@email.com] or (575) 123-4567.


Steve Jordan
Jordan Painting Company
List Of Enclosures: Copy Of Standard Contract

sample 2 - Proposal Letter To Offer Catering Services

Your Name
Name of Business
Address of Business
City, State, Zip Code


Name of Potential Client
Name of Potential Client’s Business
Address of Potential Client’s Business
City, State, Zip Code

Dear Name of Potential Client:

My catering firm can help you save 50% on the cost of your events. Because we use fresh, local foods, we can deliver wonderful dinners and hors d’oeuvres for half the price. I am confident that we can save you money on every event.

I’ve been to numerous of your events and am familiar with the quality and quantity of food you need to make them a success. 

I’d be delighted to meet you and go over menus for a variety of meals and snacks, as well as demonstrate how we serve high-quality cuisine at low pricing. 

I’ve been in the catering business for ten years and have 15 year repeat customers. We’ll have vegetarian, vegan, gluten-free, kosher, and halal options available.

Please call me at [Phone Number] or email me at [Email Address] and I will be happy to meet you at a time that is convenient for you.


Your Name

sample 3 - Proposal Letter To Offer Plumbing Services

Your Name
Name of Business
Address of Business
City, State, Zip Code


Name Of Building Manager Or Owner
Address Of Manager Or Owner
City, State, Zip Code

RE: Apartment Complex Plumbing Services

Dear [Name of Manager or Owner]:

This letter is to formally propose plumbing services for the [apartment complex’s name]. 

For the past 25 years, we have successfully maintained the plumbing systems in more than 10 apartment complexes in [CITY], and we would be pleased to provide references from our customers.

We respond to all emergency requests 24 hours a day, 7 days a week, and ensure that the plumbing in each unit is in good working order. 

When compared to calling a plumber every time there is a problem, a service maintenance contract from us can save you a lot of money.

It also relieves you of the burden of obligation. On components and labor, we offer a 90-day guarantee on repairs and new installations. 

I’ve attached a copy of the standard contract, which includes a cost estimate. It can, however, be customized to match your individual needs.

I would be happy to talk to you about our services and answer any questions. I can be reached at [555-123-4567] or at [name@email.com].


Your Name
List of Enclosures: copy of standard contract

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