Legal Question in Civil Litigation in New York

Re: valid documents

I don't know what you mean by "valid" document. It is still a document. But the oath given by the person whose statement appears on the document is not effective, so the document will not carry the same weight as an affidavit or statement under oath.

When you say the notarized signature is dated before the date the document was written, are you talking about the notary's license having expired before the date of the document itself?

Re: valid documents

I would more information. The signing of a document (i.e. contract) can only occur after the document has been drafted. Sounds like something is askew.

Re: valid documents

No. Anything written on the document subsequesnt to the notarized signature invalidates the document.