For a Subclass 189 visa with work experience in your nominated occupation, even if you do not claim the 5 points for the 18 months, the Department generally still requires evidence of your employment. This typically includes a reference letter from your employer to verify your work history and duties. if obtaining the letter could jeopardize your current job, you might support your claim with other evidence like payslips, bank statements showing salary payments, tax records, or employment contracts. While a reference letter is normally preferred, alternative documentation can sometimes be acceptable. It's important to present credible and verifiable proof of your employment, but you may explain your situation in a cover letter when submitting the application.