Proposal cover letter is written as escort of a business proposal. It is a short overview of the proposal itself. It should be professionally written. One of the mistakes of a business proposal is trying to summarize the whole business proposal in the cover letter. The summary of your business proposal should be written in your executive summary not in the cover letter. The only purpose of your proposal cover letter is to introduce your business proposal.
The first paragraph should thank the recipient, and then the second paragraph should contain something personal but still in professional way. If the business proposal is for your existing client or customer, don’t forget to mention how you enjoyed working with him in the past. And if your business proposal is for the client or company you have never done business before, make an effort to establish a working rapport through telephone conversations and email. And that way, your cover letter will not being too dry
The last paragraph of your proposal cover letter will be your expectation for the future such as your looking forward for the earning potential of your business being offered as well as the working relationship with the new client or customer.
Before writing a proposal cover letter, the proposal must be completed because the writer may have communication with the recipient that will control the tone and content of your letter.