Before we start, I'd like to clarify something.  A W-9 form is a Request for Taxpayer information and serves as the basis for the 1099 form that will be issued at the end of the calendar year.  Most companies will not issue any checks without first having this information in their hands.  Your wife will have to fill out one, no matter what (assuming she wants to be paid).Now, on to you question.  For your wife, there are two compensation options for a non-employee (i.e. independent contractor):They can make the checks payable to her personallyThey can make the checks payable to your S CorpI would advise that you have the checks made payable to the S Corp.  The primary reason is that, to a certain extent, you will avoid self employment taxes, namely FICA (6.2%) and Medicare (1.45%).Had your wife been an employee of the company, these 'payroll taxes' would be paid by the employer.  They represent a 'matching amount' that employer pays, based upon how much is deducted from an employees' gross pay for these taxes.However, when you are self-employed, rather than the employer paying these taxes, you pay this matching portion.The tax advantage of an S Corp is that the earnings of this type of entity is not subject self employment taxes, whereas, if the check is payable directly to your wife, they are.This is outside the scope of your question, but related.  The IRS is determined to get 'some' payroll taxes from your S Corp.  You must pay all shareholders who participate in the operations a reasonable salary.  In doing so, your S Corp will be required to pay the FICA and Medicare taxes for anyone on payroll.  Many S Corp owners mistakenly believe they can simply pay themselves no official salary, thereby escaping the payroll taxes.  Further reading:S Corporation SE Avoidance Still A Solid StrategyS Corporation Taxes, Self Employment Tax Savings