You may file an I-129 form to change your current status to TN-1. However, if you enter the U.S. under the Visa Waiver Pilot Program (VWPP), you cannot change your status in the U.S. All documents required to obtain TN-1 status must be submitted to the USCIS with the form. However, you can avoid the application fee by going back to Canada and applying for TN-1 status at the border. In this instance, you need not fill out an I-129, but would simply present the necessary documents to the interviewing officer.