Business is about selling goods and services at a profit. When you supply goods or services, the buyer has to pay. To indicate payment is due, the vendor issues an invoice -- a form of a bill -- the quantity of merchandise or services supplied at a predetermined price. Increasingly, many businesses now design their own official invoices using a personal computer instead of purchasing them because there's no approved standard format for the document.

Things You Will Need

  • Computer

  • Printer

  • Internet

Go to Microsoft Excel and open a blank spreadsheet and set up an invoice template. The spreadsheet is designed with fields where you can enter the invoice number, date, quantity of goods and pricing data . Put the name of your company and contact information on top of the spreadsheet. A logo is not necessary, but you can simply copy and paste one if you decide to add it.

Download a free template on your computer from the Internet. There are websites that sell templates for a low cost, but you can save money by downloading a free one from various websites including Microsoft.com, Aynax.com, Freetemplates.org and Quickbooks.intuit.com.

Customize the templates by replacing the sample information with your company's. This includes the name and contact information of your organization and the name of the person or business to whom payment is due. If you decide to add a logo and it has contact information, you don't have to repeat the same information on the invoice.

Indicate the purchase order number and the invoice number. The purchase order number helps to identify the goods for which the purchaser is being billed. What is more important, however, is the invoice number which many companies use as a control feature in their accounting processes. It is important not to repeat the same number once one invoice has been issued because the purchaser could refuse to make payment even when the figures and other details on the invoice are different.

Use a Microsoft Word document to design an invoice if that option suits you. A Word document is easy to use. Open a blank page and type the name of the company and contact information. You can copy the logo from your website, if you have any, and paste it on a Word document to make it look official. Tabulate the goods or services provided and the pricing. Provide space for an authorizing signature by accounts payable.