Does anyone know of a service that would provide to a subscriber up to date information relative to state tax withholding requirements for qualified and nonqualified plans? I would expect that such a service exists. This particular facet of retirment plan administration is not my expertise, although I can do a nice job with a DB valuation. I am hopeful that such experts do access these message boards and could point me in the right direction.

We used to use CCH http://tax.cchgroup.com (unfortunately they were a casualty of our budget cuts). They provide prompt updates on any related changes.