The income-tax form follows the kind of income, not the job title on your email signature. Using a shorter form than your facts allow is a defective return. Using a longer form than you need only adds schedules.
ITR-1 is for a resident individual with salary or pension, one house property, and interest or similar other income, inside the limit notified for the year. Capital gains, foreign assets, business income and directorship take you out of it.
ITR-2 is for individuals and HUFs who still do not have business or professional income, but who have capital gains, more than one house, foreign income or assets, or another fact ITR-1 cannot carry.
ITR-3 is the business form for individuals and HUFs — proprietors, professionals with books, and partners. ITR-4 is the shorter presumptive form under sections 44AD, 44ADA or 44AE, and only when the year’s conditions and income limit are met.
Before you file, download AIS and Form 26AS. Most mismatches we see are interest, securities sales or GST turnover that the client did not mention. The due date is whatever the department has notified for that year, not the date you remember from the previous July.