Yes, accountants can be held liable for tax mistakes made on behalf of their clients. In fact, tax laws and regulations are complex and constantly changing, and tax mistakes can result in significant financial and legal consequences. As such, accountants are responsible for ensuring that their clients' tax returns are accurate and comply with all relevant laws and regulations. If an accountant makes a mistake that results in additional taxes, penalties, or interest owed, the client may have the right to sue the accountant for damages. Therefore, accountants need to carry liability insurance to protect themselves in case of such claims.