There is no national legal standard in the USA that states what contents an invoice issued within the US to another customer within the US must include. However, accounting best practice standards dictate that the following information should be present on any invoice issued by a merchant:
✓ The full name and address of both the merchant and the customer.
✓ The business Employer Identification Number (EIN), or if you run a sole proprietorship or LLC, your own Social Security Number.
✓ The customer’s Social Security Number (if provided).
✓ The issue date of the invoice.
✓ The amount due to be paid.
✓ The deadline date for paying the amount due.
✓ The correct invoice number for the invoice.
✓ Accurate description of goods or services provided.
✓ You may be required to include sales tax in your invoice, depending on your state sales tax regulations.
✓ Any pre-arranged discounts applicable.
If one of these details is missing or incorrect, you should issue an invoice correction. If not, you run the risk of having inadequate records when it comes to filing tax returns and may risk not being able to claim back on your sales tax expenses.
There are two things you need to remember when dealing with an invoice correction. Firstly, you must issue the missing or correct information by means of a corrected invoice with a new invoice number. Secondly, your corrected invoice must clearly refer to the previous invoice it is replacing. Do not worry too much about spelling mistakes or typos – generally, if the meaning of your bill is clear, you do not need to make any corrections.