Since corporate tax rates are lower, can you save on taxes by converting a sole proprietorship to a corporation? As businesses grow, owners often consider incorporation, but depending on the industry, scale, and business direction, a sole proprietorship may or may not be the better fit.
For example, while most large businesses are corporations, some like Kim & Chang Law Firm maintain sole proprietorship status based on their business registration number. So at what point should you consider converting your business to a corporation?
The starting point for this deliberation is usually "taxes." When operating as a sole proprietor, once profits exceed a certain level, income tax and the four major insurance premiums enter a bracket exceeding 40% of pre-tax profits. At this stage, taxes and public charges account for nearly half of profits, so even if profits increase further, the actual perceived income inevitably shrinks. This is when business owners begin considering conversion to a corporation with its relatively lower tax rates.
A corporation is a very useful vehicle for business. It's the only entity that can become your property while simultaneously serving as an independent subject of rights and obligations separate from yourself. As an independent legal entity, a corporation pays "corporate tax" on its profits, just as individuals pay "income tax."
The problem is that regardless of corporate tax, you as an individual still have "income tax" obligations. Even after converting to a corporation, from an individual's perspective, "business income" merely changes in name to "salary and dividends," and the income tax burden when withdrawing funds from the corporation remains similar. In other words, a sole proprietorship has a "single structure" where business income is subject to income tax, while a corporation has a "layered structure" where corporate tax on company profits (primary) and income tax on the representative's salary and dividends (secondary) both apply.
For ease of calculation, assuming profits of 1,000, a flat income tax rate of 30%, and a flat corporate tax rate of 10%, a simple numerical comparison is as follows:
Of course, since various incidental costs are added to corporate operations, if an individual tries to take all profits immediately, the cost burden may actually be greater. Nevertheless, the reason for incorporating is clear. If the business owner doesn't withdraw all profits as salary immediately, the corporation's after-tax profit (900) is greater than the sole proprietor's after-tax profit (700). By reducing immediate taxes and reinvesting in the business, you gain momentum to plan bigger ventures. Consequently, the lower corporate tax rate compared to income tax has the same effect as receiving an "interest-free loan" from the government.
Therefore, corporate conversion is necessary when ▲you plan to expand and reinvest in the business ▲you need to enhance external credibility ▲or you plan to accumulate profits within the corporation and transfer pre-tax profits to children in the form of stock. Conversely, for business owners who spend profits as they arise or prioritize building assets in their personal name, operating a corporation with its additional costs may be unsuitable.
What ultimately has the greatest impact on profit and loss—the report card of business—is taxes. Unless establishing a for-profit corporation is fundamentally impossible as in the medical industry, corporate conversion is a deliberation that all income-generating business owners must go through. However, the key to corporate conversion is ultimately not "avoiding taxes" but "securing the opportunity cost of using money that would go to taxes for business expansion first." Since changing the business entity is a major transformation, I encourage you to carefully consider with experts how well the corporate structure aligns with your business direction before making a decision.