How To Write A Decline Letter For A Project . However, we are unable to proceed as your {job designation e.g., supplier} at the moment. Thank you for the offer and the interest in working with {company name} on this. Sample Proposal Rejection Letter (Decline Bid or Business Proposal) from www.wordtemplatesonline.net Close with a positive remark, perhaps suggesting future possibilities for business together. Taking a look at the materials, it seems. Thank them for their proposal.