Business agreement letters should include sections with specific details of which services are provided and not provided, the expected final product, fees and terms, according to About.com. Language should be simple and relatively informal.
About.com recommends that an agreement letter between an independent contractor and a business client should start with "Letter of Agreement" at the top. Below the title on separate lines should be the client's name, the project name and the date of the agreement. The first paragraph states that the contractor is providing certain products or services to the client. Each party can be assigned a short name for easy reference throughout the letter, for example, "Editor" instead of a lengthy business name, and "Client" instead of the client name.
The next section uses bullet points to list which services are provided and not provided, About.com suggests. Details should be as specific as possible, for example, "Content editing and proofreading using Microsoft Word with track changes on." A disclaimer that reads, "I have not agreed to provide the following services," may be followed by what the provider is not expected to do, such as convert files to other formats.
Next is a section on delivery explaining how both parties measure progress and what the final product is, About.com recommends. Then the agreement includes a section on payment including fees, dates due, mode of payment and legal action to be taken if payment isn't made.
Both parties must sign at the bottom of the letter.