<prompt> Human: I was under the impression that I had until the end of February to submit a new W4? Any advice appreciated  <response>: Employers are required to comply with the new tax withholding tables by February 15. Depending on when your payroll department does payroll and your pay date, this might be part of the new tax law requirements. I own my own business and just updated our payroll. I was reading online that larger employers might require new W4s be filled out. 