No business, big or small, will last long if it doesn’t get promptly and properly paid for services rendered and products delivered. These guidelines explain the characteristics that constitute a proper estimate, invoice, and billing statement. The accompanying templates will serve as practical examples of these vital financial documents.

From the guidelines:

An invoice is a request for payment after a service is performed or a product is delivered. If one was created, an invoice should closely mirror the terms agreed upon in the original estimate. Details for invoices vary by the products or services involved, but in general an invoice should include:

• The date the invoice was presented to the customer
• An accurate and valid billing address for the customer receiving the invoice
• Systematically created identification numbers for the invoice and the customer so each can be easily referenced in the future
• A clear itemized statement of the service(s), work, or product(s) performed and/or delivered, and the amount being invoiced for each
• A clear and accurate statement of the total amount of the invoice
• A clear statement of when, how, and where payment is to be remitted
• If you have a preferred payment option, it should be clearly stated on the invoice
• A statement of appreciation for being a customer

Beyond creating the invoice, every SMB should have a documented procedure for tracking and aging invoices to make sure that each invoice is submitted in a timely manner and that each invoice is in turn remitted in a timely manner. If an invoice says it is payable in 10 days, someone needs to be responsible for determining whether it’s paid on time.