Which business form combines the advantages of single taxation and unlimited membership?

The Limited Liability Company (LLC) is the business form that effectively combines the benefits of single taxation and the ability to have an unlimited number of members. LLCs are treated as pass-through entities for tax purposes, meaning that income is not taxed at the corporate level. Instead, profits and losses are reported on the individual members' tax returns, thereby avoiding double taxation that typically affects corporations.

Additionally, LLCs allow for an unlimited number of members, facilitating easier capital accumulation and broader participation than structures such as sole proprietorships or partnerships, which can involve limitations. This structure provides the flexibility of a partnership or sole proprietorship while offering protection against personal liability for business debts, which is a key advantage compared to other forms of business organization.

Therefore, the LLC is an optimal choice for individuals or groups seeking a business model that allows for both single taxation and expansive membership.