As used in Spanish procedure, these five terms all denote instances in which a judge may refrain from hearing a case (se aparta del caso). They are often confused in translation and are not interchangeable. Abstención and recusación describe instances in which a judge refrains (or is asked to refrain) from hearing a case due to a conflict of interest or for other legally-determined reasons. Inhibición, declinatoria and inhibitoria refer to circumstances in which a judge may refrain from hearing a case due to a lack of jurisdiction or improper venue.

A judge’s duty to withdraw from a case due to a conflict of interest or on other legally-established grounds (deber de abstención por causas establecidas legalmente) is the “duty to recuse himself.” When there are grounds for recusing themselves (causas de abstención), judges as well as court personnel, prosecutors and expert witnesses (funcionarios de la Administración de Justicia, fiscales y peritos) are obliged to recuse themselves (abstenerse) and withdraw from the case. If a judge does not recuse himself when deemed warranted, the parties and the public prosecutor (las partes y el Ministerio Fiscal) may likewise file a “motion to recuse” or “motion for recusal” (called incidente de recusación). Thus, in this context the verb abstenerse is “to recuse oneself”, while recusar is used when a third party recuses a judge or other official. In their noun forms abstención denotes a judge’s recusal of himself, while recusación is the recusal of a judge on the part of a third party.

In contrast to the above, even if he would incur no conflict of interest a judge may voluntarily “decline jurisdiction” (declararse incompetente, literally, “declare that he lacks jurisdiction”) if, according to the rules of procedure, he believes that another court has proper jurisdiction over the matter in dispute. In Spanish this “declining jurisdiction (in favor of another court)” is expressed as inhibirse (en favor de otro juzgado/tribunal), and in its noun form, inhibición denotes a judge’s voluntary “relinquishment of jurisdiction.”

In other respects, if a judge who lacks jurisdiction (juez incompetente) does not decline jurisdiction sua sponte (inhibirse de oficio), a party to the proceedings may challenge the court’s jurisdiction by filing one of two possible motions known respectively as declinatoria and inhibitoria. Both of these terms may be appropriately rendered as “motion challenging jurisdiction,” “motion to relinquish jurisdiction” or, under certain circumstances, “motion to dismiss for lack of jurisdiction.” If the case specifically involves a lack of territorial jurisdiction (falta de competencia territorial), declinatoria and inhibitoria may also be translated as “motion alleging improper venue.”

The difference between declinatoria and inhibitoria lies with the court where the motion challenging jurisdiction is filed. Declinatoria is a motion filed with the court that allegedly lacks jurisdiction (tribunal incompetente), asking the judge to decline jurisdiction (inhibirse) in favor of another court. Inhibitoria is a motion filed with the court deemed to have jurisdiction or proper venue, asking that it declare itself the court of competent jurisdiction (que se declare competente) and to petition the court presently hearing the case to relinquish its jurisdiction (que se inhiba) and transfer the case to that court.

In summary, the above terms are all used in instances in which a judge may refrain from hearing a case. Abstención and recusación are used when the reasons for doing so involve a conflict of interest or other legal impediment, while inhibición, declinatoria and inhibitoria involve circumstances in which the court lacks jurisdiction to hear that case.