Maybe. First point you do not register a business as 1099 as you dont paypeople on a 1099. All of the income your wife receives related to the blogwill be taxable income whether she receives a Form 1099 for that income ornot. Your wife may want to create a legal name andor legal entity for thebusiness and may be required to register with your state or with other statesif she wishes to conduct business within the state. Second point and the more important point There is a chance that theoperation will be considered by the IRS to be a hobby and not a business. SeeBusiness or Hobby Answer Has Implications for Deductions on the IRS Web site.And if the operation is considered to be a hobby then you wont be able totake losses from that operation to offset other income. In my experience online blogs are generally hobbies in the IRS sense notbusinesses. Even when people make money from them which most people dont they generally dont run them as profitmaking entities but as sidelines away to earn a little extra income. Now if your wife is truly operating a business keeping books seeking ourinvestors looking for ways to grow income from the blog etc. then you canby all means treat it as such and deduct any losses from your joint income.But you had better be able to document to the satisfaction of the IRS thatyour wife is operating the business with profitmaking intent.