Though I appreciate your need to be thrifty when it comes to starting a new business, this sort of money-saving approach is inadvisable. Occasionally a company will have a “division” or some other kind of structure that makes sense by way of keeping all things under one umbrella. For example, a hardware store may open a division for its garden center. But if the businesses aren’t closely related like that, then combining could lead to myriad problems: claims for one business will easily attach to the other business, books and records for one business will be discoverable in a lawsuit against the other business, accounting will be harder to track. The list goes on. Just don’t do it. But click here to see my FAQ on whether you need an entity for your business at all.