¡La Esquina de la Gramática! Rule 7

Yes! Capitals letters in Spanish need an accent mark

People have always asked me about this rule, and my answer has always been the same: Capital letters should always be written with accents marks, if they have an accent mark according to the Spanish grammar rules. Examples:

UNA OPCIÓN DE SALUD

Su hijo se llama Ángel

The only capital letters that don’t have accent marks are the ones that are part of acronyms, for example: CIA (Central Intelligence Agency). According to the Spanish grammar rules, the letter “I” should have an accent mark, but not in this case because it is part of an acronym.

Source: http://www.rae.es