Question: For TN visa holders who want to renew their TN (same employer) for another three years, can they file their own I-129 petition or does their employer have to file the I-129?

Reply: An individual cannot self-petition for TN visa status, and as such, cannot file an I-129 petition independently on their own behalf. Just like with the TN Employer Support Letter that requests work authorization for a TN visa worker, an employer must also sign off on the I-129 mail-in petition that requests an extension of or change to TN status on behalf of a worker. Whether the employer completes the form and ships the petition to USCIS, an attorney, or the worker themselves does not matter, but a representative from the employer needs to sign the I-129 form in order for it to be accepted by USCIS.