While LLCs, S-corps, and partnerships are all separate business structures, they all pass profits and losses directly to the owners.
LLC
LLCs provide owners (also known as members) limited liability. However, they are less susceptible to strict compliance requirements than a corporation.
LLCs offer flexibility with taxation, where you can elect pass-through or corporation taxation. Note that the default taxation for single-member LLCs, a popular option for solopreneurs, is the same as sole proprietorships.
For example, assume Bob owns a gift shop as an LLC. The gift shop’s profits and losses pass through to Bob’s personal tax return. Bob would list his LLC’s profits and losses on Schedule C, which he’ll attach to his 1040 form.
S-corp
An S-corp is not a business entity type but a tax election that LLCs or corporations can make with the IRS. An S-corp’s income taxes flow through to its owners.
For example, if Bob’s gift shop elects S-corp taxation he would file Form 1120-S as an information tax return. He would pay no corporate income tax, and the income would flow through to his personal tax return.
Partnerships
With partnerships, you divide the business income among the owners. The partnership files an information return, Form 1065, and sends each partner a Schedule K-1. The K-1 will report each partner’s share of business profits.
If Bob’s gift shop operates as a partnership, he would need to file Form 1065 as an information tax return. He would pay no corporate income tax, the income flowing through to the partners.
Note that the IRS treats multimember LLCs like partnerships for tax purposes.
Sole proprietorship
With a sole proprietorship, there is no separation between you and your business. This is the default business structure unless you file for a different one. A sole proprietorship is best for individuals who need simplicity and don't mind being personally liable for any risks.
For example, if Bob owns a gift shop as a sole proprietor, he would report the profits and losses on Schedule C of his personal tax return. Bob would add the business profit from Schedule C to his other income and then calculate the income tax at his personal tax rate.