How do I add my cleaning business to my s-copr day care business?

Unless the S-corp day care business will have the same ownership as the janitorial business you will need to establish a separate entity. You will want to set up a separate entity for each business anyway for liability protection purposes. In addition, there may be advantages to setting up the new entity as a limited liability company as opposed to an S-corp. For instance, if distributions will be made out of the entity in a manner other than pro rata based on ownership, an LLC provides the required flexibility. There are advantages and disadvantages to both structures so you will want to talk to your CPA and a business attorney licensed in your state about what you want to do in the business, capital and ownership structure and exit plan.