Not in all cases. The Four-eyes method is frequently sufficient when applied to common commercial contracts. This indicates that two trained translators who are not related to one another translate and proofread the text in order to assure a high-quality final translation. However, sometimes court records or other official contracts need to have the accuracy of the translation verified by a certified translator (by attaching an official seal to the document). Yet, every country has different requirements, but in either case, contract translators must be able to demonstrate their proficiency and legal knowledge.