In Online Banking, click on ‘Invoicing’ in the main menu. After choosing to create a ‘New Invoice’ you’ll need to add some important information to make up your invoice. First you'll need to select a customer, or create a new one. You’ll be able to add a title, Purchase Order (PO) number, a message to your customer, due date, supply date, and the line items you’re invoicing for. For each line, you can specify a description, price, quantity and VAT rate (if applicable).
Once you've done this, you can click out of the invoice, and it will be saved as a draft. You can download it to see what it will look like, make any edits that you want, and then click to finalise. This will move the status of the invoice to "awaiting payment".