Final answer:
If an applicant's last name is incorrect, they should contact the company or organization they are applying to and address the issue with the appropriate department or individual.
Step-by-step explanation:
If an applicant's last name is incorrect, they should contact the company or organization they are applying to. They should address the issue with the appropriate department or individual responsible for managing applicants. In some cases, the applicant may need to submit a formal request in writing, providing details of the error and the correct information. It is important to follow the specific instructions provided by the company or organization to ensure prompt and accurate resolution of the issue.