Limited liability is where a person's financial liability is limited to a fixed sum, most commonly the value of a person's investment in a company or partnership. If a company with limited liability is sued, then the claimants are suing the company, not its owners or investors. A shareholder in a limited company is not personally liable for any of the debts of the company, other than for the amount already invested in the company and for any unpaid amount on the shares in the company, if any. The same is true for the members of a limited liability partnership and the limited partners in a limited partnership. By contrast, sole proprietors and partners in general partnerships are each liable for all the debts of the business (unlimited liability).
If shares are issued "part-paid", then the shareholders are liable, when a claim is made against the capital of the company, to pay to the company the balance of the face or par value of the shares.
Although a shareholder's liability for the company's actions is limited, the shareholders may still be liable for their own acts. For example, the directors of small companies (who are frequently also shareholders) are often required to give personal guarantees of the company's debts to those lending to the company. They will then be liable for those debts in the event that the company cannot pay, although the other shareholders will not be so liable. This is known as co-signing.