It is required to file Form I-765WS together with Form I-765, Application for Employment Authorization, only if you are applying for work permit under the following eligibility categories: Deferred Action or Deferred Action for Childhood Arrivals (DACA). In all other cases, you do not need to complete Form I-765WS.
When determining your eligibility for work authorization, USCIS will review your current annual income, annual expenses, and the total current value of your assets. In order to show an economic need to work, you will have to provide this financial information on your Form I-765WS, Form I-765 Worksheet. If you want to provide an explanation, you may complete Part 3 of the worksheet, and USCIS will take it into consideration. Meanwhile, it is not obligatory to submit any supporting documentation. Also, you do not need to include other household member’s financial information to establish your own economic necessity.