Technically, it is the practice of translating a text that has already been translated into a foreign language (TL) back to the original language (SL) – preferably by an independent translator other than the original translator.

Back translation is normally deployed for the purpose of verifying the quality of the finalized product. Sometimes it does improve the readability, accuracy and validity of a translation by requiring that the quality of a translation is verified by a different translator translating back into the source language (LOTE).

Back translation is not routinely performed in that the majority of the clients might still favour traditional proofreading rather than back translation. Original version and back translated version are compared after back translation. By and large, owing to its high cost and various other reasons, back translation is not being extensively applied, but in situations which entail high risk and high return, it could be worth the financial investment.