You'll need also a Letter of employment for the time you were working for your employer, including NOC, Salary, duties, dates and worked hours. You may get an "offer letter" after interviewing with an employer AFTER you obtain your permanent residency.Learn everything about job offer letters for immigration, including eligibility criteria, required documents, and the process. Why is an employment letter needed? The Letter of employment is the same thing as the job reference letter. It is evidence for the jobs you listed in the Job history. The applicant must give a letter from the organization with all the specific information. This letter is called an Employment Reference Letter. Start the process early: It can take some time to get work reference letters from past employers, especially if you have a long career history. It has to include your daily tasks and responsibilities, and should make up most of the content of the letter.