Whether you need it or not depends on the document and your jurisdiction. If you can choose between the two methods of testifying to a favorable document, it is always better to contact the notary. While it is acceptable for objective parties to witness a document, courts are often more comfortable with a notary`s signature. When it comes to commercial real estate, some states want mortgages or county or state documents to be registered. In Florida, documents must have two witnesses to be recorded and validated.