The manner in which a document is certified by a translator may vary. However, in all instances, the documentation being certified usually comes with an attestation or declaration and must bear the name of the translator in block letters along with her/his signature, affiliation to the accrediting body and accredited translator registration number. Many certified translators have adopted the practice of applying an official seal (ink stamp or embossed seal of their affiliation) to the translation and/or accompanying declaration, though this is not a formal requirement.

Depending on the circumstances, a sworn statement (affidavit or sworn declaration) from the translator and/or the notarization of the document(s) translated or source documents may be required. Whether or not a sworn statement or document notarization is necessary is determined by the institution or body that is demanding the certified translation.

In the United States, any translator or any translation company representative, regardless of credentials, may provide a certification that in the words of the US Citizenship and Immigration Service is constituted of a “certification [that] must include a statement that the translator is competent to translate the document, and that the translation is true and accurate to the best of the translator's abilities.”

In other words, insofar as US Citizenship and Immigration Services requirements are concerned, a translator need NOT be "certified" in order to provide a certification. 

In the United States a so-called “certified translation” consists of the following:

1. The original document(s), referred to as the source-language document(s)

2. The translated document(s), referred to as the target-language document(s)

3. A statement that is referred to as a “certification” that is signed by a translator or translation company official attesting that they are of the belief that the target-language document(s) is (are) an accurate and complete translation of the source-language document(s).