All government contract protests should be filed within 10 days of an award action, right?  Wrong!  The pertinent regulation may state that a protest is timely only if filed “10 days after the basis of the protest is known or should have been known,” but “should have been known” can be expansive, as occasional GAO rulings have shown.  Sometimes that could be only when the unsuccessful offeror receives a de-briefing or summary letter outlining the reasons why they were not awarded a contract.  In one case involving a GSA Multiple Award Schedule contractor, a protest was deemed by GAO to be timely 33 days after award because the basis for the protest was only known to the contractor when they received a summary letter from the buying agency on the alleged deficiencies in their offer (Castro & Company LLC, B-412398).  GAO stated, “the substance of the evaluation and the source selection rationale” were only made known to the contractor in the letter and noted that the subsequent protest was then filed within the required 10 days.  Of course, any company wanting their protest to result in at least a temporary “stop work” requirement is better off filing a protest as early as possible.  Even a successful protest may result only in the agency being essentially told “don’t do it again” if work has already commenced, or even been completed.  Regular readers know, too, that we believe that occasional protests, founded upon a real issue, are a good practice.  They keep agencies honest and do little to harm working relationships.  Being known as a “no protest” company is worse than filing untimely protests