Making An Invoice

If you own a business who sells a product or provides a service to clients before they pay you, a customer invoice is the ideal way for you and the client to know exactly how much money is owed for the job or item(s) purchased. The invoice serves as a record of goods or services sold to the customer or client.

What Information is required on an Invoice?

Company Details

  • business name and if relevant trading name
  • postal address, email address, website address, contact telephone and facsimile numbers
  • Australian Business Number (ABN) or Australian Company Name (ACN).

If you have a logo, include it in the header to the left or right of your business name. If your business name is part of your business logo, you can use the logo in place of your name.

It is not necessary to include a company logo, though it can help lend your invoice a professional air.

If you don’t have a logo and wish to make one, see How to Make a Personal Logo.

Invoice Number

To stay organized and make the tracking easier for your tax season, we strongly suggest providing unique and sequential invoice number for every invoice you send.

Invoice Date

The issue date for the invoice. Pro tip: Getting your invoice out in a timely manner can help you improve cash flow and get paid faster.

Client Details
Include the customer name and address. You may also put the phone number for reference.

Payment Term
States how you would like to receive the payment. You may need to state the payment due date also.

Shipping Term
States how the items will be shipped to the customer

Contact Details

You need to add your own contact details, which are best placed in the footer of your invoice. These include your name, address, phone number and email. If you’re a limited company, include your company number. (If you’re registered under one name but trade under a different one, include both.)

Your client’s details go in the top left corner. If you provide your services through an agency, it’s common practice to enter the agency as the client.


You should include the following dates:

  • Date: the date the invoice was raised.
  • Due date: the date by which payment should be made. Normally 30 days after the invoice date.

Late Payments
To help protect yourself from late payments you may quote the Commercial Debts Act which allows you to charge a late payment fee of £40 once your stated terms are exceeded. Include the following wording:

‘We understand and will exercise our statutory right to claim interest and compensation for debt recovery costs under the late payment legislation if we are not paid according to agreed credit terms.’

Format of Invoice
If your customer accepts an electronic format of invoice, you should prepare your invoice in PDF format.
PDF format is good for electronic delivery as:
(1) PDF cannot be altered,
(2) it can be opened freely in different platforms,
(3) the layout of the invoice can be kept and printed correctly in different platforms.

Important things to remember:

Generating an invoice is the sole responsibility of the vendor/supplier. Caltech employees are never to create an invoice on behalf of the vendor/supplier. This is an important segregation of function and audit compliance issue. It is important that Caltech maintain a certain professional distance with the vendor/supplier community.

Invoices must contain complete information. Vendors/suppliers must provide the detail on their invoice for Payment Services to effectively process the invoice for payment. The details required are indicated on the pages to follow.