Proofreading means the revision of a translation done by a third party. If that translation has too many problems — which is often the case with machine translation or if a text was translated by a non-native speaker – then we have to verify the translation against the source text. If the correction requires as much time as a new translation, the quote will reflect this. If the quality of the translation is so low that we have to produce an entirely new translation, our usual translation rates apply. If the quality is relatively high and the translation requires only small corrections (spelling, grammar, style, etc.), the applied rate is usually one-third of that of a translation.