Now that you have filed your taxes and expect a sizable refund, it is time to consider adjusting your withholding. While nobody enjoys writing a check to the IRS, one should also avoid giving Uncle Sam an interest-free loan. Withholding is adjusted by submitting a W-4 to your employer, which can be done at any time. Kiplinger has a withholding calculator on their website www.kiplinger.com/tools/withholding which is much easier to use than the IRS W-4 worksheet. Also bear in mind that with the new tax laws, high income earners could end up owing more in taxes and wind up underwithholding. In this case one would increase withholding so as to avoid underpayment penalties.