Certified translation and credential evaluation

Two different things that are constantly confused. A certified translation is a word-for-word rendering by a recognised translator with their statement attached — it changes nothing, it only makes the document readable. A credential evaluation is a judgement by an approved body about what your qualification is equivalent to within that country's own system.

You need a translation whenever the original is not in the language of instruction. You need an evaluation only when the institution asks for one, and they will name the bodies they accept. Paying for an evaluation from a body they do not accept is the most common wasted expense in this entire process. Ask before you pay.