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. Upon receipt of your bid, you will receive a reply indicating your bid has been received.This must include the RFP title, RFP number, complete vendor name and mailing address as shown in Appendix 5. To write a proposal letter, follow these simple steps. Alongside our guidelines, we also offer proposal letter templates and examples. Provide the name of your proposed Engineer-of-Record. ("EOR") and include: (a) the EOR's key personnel (e.g.