Here are a few key tax-related deadlines for businesses during Q1 of 2019. JAN. 31: File 2018 Forms W-2 with the Social Security Administration and provide copies to employees. Also provide copies of 2018 Forms 1099-MISC to recipients and, if reporting nonemployee compensation in Box 7, file, too. FEB. 28: File 2018 Forms 1099-MISC if not required earlier and paper filing. MAR. 15: If a calendar-year partnership or S corp., file or extend your 2018 tax return. Contact us to learn more about filing requirements and ensure you’re meeting all applicable deadlines.