A copy of the initial Form 65, Uniform Residential Loan Application, as well as the final signed application, must be included in the Mortgage file. The final signed application must match the file documentation. If there are any discrepancies between the information on the application and the information in the credit, income and assets verifications, a written explanation of such discrepancies must also be included in the Mortgage file.
Additional Resource: http://www.freddiemac.com/singlefamily/guide/bulletins/pdf/032217Guide.pdf#page=194