Being the sole owner of a company usually means that you are responsible for that company's direction and management. While being a sole owner often means being a sole proprietor, it can also mean being a single shareholder in a private corporation or limited liability company. Proof of company ownership documents depend on the type of entity you have.
TL;DR (Too Long; Didn't Read)
A DBA filing, stock log and articles of association or organization can all prove ownership of a business. It depends on the structure of your company.
Proof of Business Ownership for Sole Proprietorship
A sole proprietorship is a business owned by one person that is not a separate business entity from the owner. Some sole proprietorships operate under a fictitious name, known as a "doing business as" name, allowing the owner to create a separate public business image. The tax liability of a sole proprietorship is tied to the owner's tax identification number, the Social Security number.
The easiest way to show proof of business ownership for sole proprietorship is to provide a copy of your tax return with the Schedule C attachments for your business. You can also produce a copy of the DBA filing from your city or county that states that you established the business name.
Corporation Proof of Business Documents
There are two types of corporations, an S corporation and a C corporation. An S corporation operates very similarly to a sole proprietorship regarding taxation. The sole shareholder filters all taxes to his own personal Social Security number. A C corporation files under it own taxpayer ID number, called an Employer Identification number.
For proof of company ownership documents for an S corporation, you can provide a copy of your tax returns or the articles of incorporation with the stock log of all issued stock. If you are the sole owner, there is only one person with stock — you. The latter is also true of a C corporation. The articles of incorporation list all original owners, while the stock log lists any subsequent stock recipients.
Limited Liability Company Ownership Documents
A limited liability company is a cross between a partnership and a corporation. Members establish the business entity to reduce liability, but have the option to pass taxes to the members' personal Social Security numbers. The LLC can obtain an Employer Identification number if members elect to do so.
Tax returns and the articles of organization serve as proof of business documents. Articles of organization are are similar to a corporation's articles of incorporation, listing the members who established the business. As the sole owner, only your name is on the articles of organization, with no additional members added through stock issuance.
Things to Consider
Giving potential investors full disclosure is the ethical and legal thing to do, and you could be held personally liable for any misrepresentations of your company. Between tax returns, business entity filings and stock logs, you should have all the documentation required to prove you are the sole owner of the business. Company financial statements may also show that no other parties are receiving profits from the company.