S corporations have a few disadvantages relative to traditional C corps, mostly in the limits imposed on shareholders: No more than 100 shareholders are allowed, and they cannot be foreigners or other corporations. Also, owners can create only one class of stock. Plus, there are some fairly complex shareholder compensation requirements. These focus on the classification of payouts as either “wages” or “distributions.” The SBA says that owners need to pay attention to “low salary/high distribution combinations” because these are red flags for the IRS.