Yes, as a sole proprietor, you can operate multiple businesses simultaneously under a single legal entity. When filing your taxes, you are required to complete a separate Schedule C for each business to accurately report income and expenses associated with each venture. This means that even if you own a personal training service and also run a side hair-cutting business, you will need to prepare individual Schedule C forms for each, detailing the specific income, costs, and deductions related to each activity. While legally you are not required to establish separate entities for each business, maintaining clear financial records for each helps ensure proper tax reporting and compliance. This flexibility allows entrepreneurs to diversify their income streams without the need for forming multiple legal entities, simplifying administration while still adhering to tax regulations.