A professional invoice should include: A clear and concise description of the services provided, including dates and times. A breakdown of charges by service or project, with a total amount due. Your business name, contact information, and any tax or identification numbers required in your jurisdiction. The client's name and contact information, including billing address. Payment terms, including due date, accepted forms of payment, and any late fees or penalties. Any additional terms or conditions agreed upon in advance, such as retainer fees or project milestones. By providing clear and comprehensive invoices, you can ensure that your clients understand the scope and value of your work and minimize the risk of disputes or payment delays.