In Maunlad Transport, Inc. v. Manigo, Jr.,[28] this Court explicitly declared that it is mandatory for a claimant to be examined by a company-designated physician within three days from his repatriation.  The unexplained omission of this requirement will bar the filing of a claim for disability benefits.    The NLRC and the Court of Appeals determined that petitioner did not observe the established procedure as there is no proof at all that he reported to the office of the respondents.[29]  We see no reason to depart from their findings.  While petitioner remains firm that he reported to the office of the respondents for mandatory reporting, the records are bereft of any proof to fortify his claim.  The onus probandi falls on petitioner to establish or substantiate such claim by the requisite quantum of evidence. There is absolutely no evidence on record to prove petitioner’s claim that he reported to respondents’ office for mandatory reportorial requirement.  Petitioner therefore failed to adduce substantial evidence as basis for the grant of relief.   The general principle is that one who makes an allegation has the burden of proving it.  A party alleging a critical fact must support his allegation with substantial evidence.  Any decision based on unsubstantiated allegation cannot stand as it will offend due process.[30]     In labor cases as in other administrative proceedings, substantial evidence or such relevant evidence as a reasonable mind might accept as sufficient to support a conclusion is required.[31]             The oft repeated rule is that whoever claims entitlement to the benefits provided by law should establish his or her right thereto by substantial evidence.[32]  In Wallem Maritime Services v. National Labor Relations Commission, [33]  this Court made an exception regarding the compulsory reporting requirement and emphasized that this rule is not absolute.  The Court explained that the seaman therein was physically incapacitated from complying with the requirement observing that the seaman was already terminally ill and for a man in that condition and in need of urgent medical attention, one could not reasonably expect that he would immediately resort to and avail of the required medical attention assuming that he was still capable of submitting himself to such examination at that time.   Regretfully, we cannot apply Wallem to petitioner’s case as the circumstances in that case are not the same herein. Petitioner is not similarly situated in that there is no showing that he is likewise physically incapacitated to