In the context of appealing a decision of the tax authorities, I believe you will find that "recurrir" is the appropriate term, rather than "apelar". "Recurso" is the generic term in Spanish for all types of appeals, while (at least in Spain) "recurso de apelación" is a specific type of appeal (a "recurso devolutivo" or appeal to a court ad quem) and "apelar" is, thus, used when appealing the decision of a lower court. When speaking of appealing any type of decision of the tax authorities, the expression used is "derecho a recurrir."


...los principios y derechos generales de los contribuyentes y los derechos y garantías en los procedimientos tributarios y, en concreto, en los de inspección, recaudación y sancionador, así como el derecho a recurrir y las reclamaciones económico-administrativas.
www.fundef.org/docs/50sedf.pdf