你问为什么他现在要？说不定人家开始专业懂法了

http://http-download.intuit.com/http.intuit/CMO/payroll/government_stuff/W4_Tip_Sheet.pdf

 

IRS Review: You are required to keep a Form W-4 on file for each employee for at least four years after the date the employment tax becomes due or is paid (whichever is later). When requested, you must make original Forms W-4 available for inspection by an IRS employee. You may also be asked to send copies of certain Forms W-4 to the IRS.