Proposals can be rejected during the opening if they do not comply with both the instructions and the formal criteria set out in the solicitation documents.

The most common reasons for bid rejection are non-compliance with the requirements for documentation that are stated in the bid (for instance, failing to include a signed and stamped proposal submission form).

For RFPs, the most common reason for rejection is non-compliance with the requirement to use two envelopes when submitting the proposal (instead submitting both technical and financial components in a single envelope).