Rule 90.903 Testimony of subscribing witness unnecessary

If someone signs a document as a witness, you do not need to bring that person to court to prove the document is real. Other ways of proving a document is authentic are perfectly acceptable.

There is one exception. If a specific law requires a witness signature on a document, like a will, that law might also require the witness to testify in court. In that case, you would need to follow whatever that law says.