The benefit of being an SOT and FFL licensee is that you can sell or manufacture a wide range of firearms products. You need to pair an SOT with its corresponding FFL, it is the only way for a business to obtain, manufacture, and resell firearms falling under the NFA guidelines.Also, while you can pay per-item taxes on NFA items, this can quickly add up. By acquiring an SOT license, you can avoid the expensive nature of trading these products by paying a single-year tax.