In this article, we discuss how to write a business proposal letter and we offer sample letters and templates you can use as a guide. To write a proposal letter, follow these simple steps.Alongside our guidelines, we also offer proposal letter templates and examples. How do you write a business proposal letter? This letter serves as notification of intent to submit or not to submit a proposal for THE SOUTH FULTON FREE. STANDING ED. RFP Numbers: Q2024016. This letter serves as notification of intent to submit or not to submit a proposal for THE SOUTH FULTON FREE. STANDING ED. RFP Numbers: Q2024016.