As Per Wikipedia
An invoice, bill or tab is a commercial document issued by a seller to a buyer, relating to a sale transaction and indicating the products, quantities, and agreed prices for products or services the seller had provided the buyer.
Payment terms are usually stated on the invoice. These may specify that the buyer has a maximum number of days in which to pay and is sometimes offered a discount if paid before the due date. The buyer could have already paid for the products or services listed on the invoice. To avoid confusion, and consequent unnecessary communications from buyer to seller, some sellers clearly state in large and/or capital letters on an invoice whether it has already been paid.
"Your business name is one of the most important elements of an official invoice template. It shows who you are and establishes your brand. Adding contact information lets your clients know how to contact you if they have any questions about the invoice It also allows them to contact you for future work. You can add your address and cell ph number"
As Shown in image..
To stay organized and make the tracking easier for tax filings. It’s best to provide a unique and sequential invoice number for every invoice you send. We give this optional as user have control over it
By default current date will be today’s date in us date format, but you can change it You can also set due date, keeping it empty wont show due date in final invoice
Who this invoice is intended for and their contact information.
Specify Description, Quantity, Rate, Amount and Subtotal. The more details you include on the invoice, the better. This way, your client will know exactly what they are paying for upon receiving the invoice.
Depending on your jurisdiction and type of business, the tax requirement can vary. Refer to your local tax office and include the appropriate tax amount on the invoice. It can be easily customized from setting and next time your setting will be saved for new invoices.
If you are offering a discount to a valued client, include the number here. This can be a percentage or actual amount.
A simple, personalized note will leave a good impression with the client and increase the chance of an invoice getting paid faster. You can also include payment instructions, warranty information, discount details or anything else relevant to the job.