Mistakes can tarnish your reputation or create a poor impression with your customers. Let me cast a professional eye over your documents to avoid a serious blunder.
Proofreading is the process of scanning a text for grammar, syntax, punctuation and spelling errors, performed on a monolingual document. It does not include comparison between source and target language documents.
Editing is the process of bilingual revision. The translation is compared to the source text sentence by sentence and checked for accuracy, completeness, terminology, clarity, style and register. Please note that editing is much more time-consuming than proofreading.
Full bilingual revision is editing followed by proofreading.
Both proofreading and editing are charged by the hour. Time needed for the services depends primarily on the quality of the text. If the translation is really poor, it may be faster and cheaper to retranslate the text.