You may need to prove that you're unemployed for a number of reasons. You might need proof to obtain social services or to receive assistance from a nonprofit organization. Benefits from public and private organizations that serve the poor often require some type of proof of your eligibility before they will help you.
Apply for Insurance
As soon as you become unemployed, apply to your local employment office for unemployment benefits. Unemployment insurance, or UI, is a federal/state benefit that pays you when you lose a job through no fault of your own. Apply for the benefit even if you quit or worked as a subcontractor or independent contractor because you don't know for sure if you qualify for unemployment insurance until you apply.
Wait for Your Letter
The agency then has a duty to verify your claim. It will require your former employer to answer a questionnaire verifying your employment and the details of your termination. After receiving the employer's response, the agency will send you a letter allowing you benefits or denying your eligibility. Either way, the letter proves you lost your job.