The mandatory grounds for refusal are basically the following: a) the fact that the certificate is incomplete, b)an eventual breach the principle of ne bis in idem, c) the facts under investigation in the foreign state are not punished as criminal offence in Portugal, (with the exception of the offences mentioned in article 7 of the FD that won´t be verified on double criminality d) the criminal proceedings are statute-barred under the internal law, and Portugal has jurisdiction over the facts, e) there is an immunity of the defendant that under Portuguese law would prevent the execution of the decision, the person subject to the decision would not be be charged in Portugal by reason of age, f) trial in absentia, except if : the defendant was summoned of the scheduled date, or if it may be unequivocally established that the person was informed that a decision would be handed down in his/her absence, if the person was summoned of the trial and was represented by a counsellor, or if the person has a right to a re-trial, after being served with the sentence.