Investors & landlords

I added wife to an account at Schwab and tipped the lady to take care of paperwork. I just signed and did not notice She had checked the withholding box, darn it. It was not checked on my original application.   I did not discover for several months.  Now I have thousands of dollars being held by IRS -  I assume that I just enter the total and wait to see if IRS want me to document?