What is an invoice number or invoice ID?

A person reviews a PDF invoice for a business on a laptop.

Learn more about invoicing numbers, the best practices for creating a numbering system, and why these numbers are essential to keep workflow moving in your business.

An invoice is a formal document — bill — that allows you to get paid for your goods or services. An invoice number is just one of the many elements that make up a standard invoice.

What is an invoice number?

An invoice number is simply a unique record number assigned to each invoice you issue. This number can be automatically generated by invoicing software, if you use it, or you can manually create one when issuing the invoice.

Invoice number meaning is subjective, and generally acts as a form of record for the vendor and the customer. You can use these as references for billing questions, income tracking and taxes later on. They define invoice and assign it to a specific purchase at a set time in your shop’s history.

How to number invoices.

There are no particular financial regulations you need to heed when it comes to creating a numbering system for your invoices, but it is advisable to have a clear and consistent system that works for you. Here are some standard practices:

Choose a numbering system that makes the most sense for your business, and remember to keep each invoice sequential to avoid any confusion. Start with invoice “0001” and continue your numbering from there.

What is an invoice number used for?

Beyond being a simple reference to look back on later, an invoice number can also apply to certain payments — such as tabs that remain open or goods that may have been purchased under a discount.

An invoice number example could include different letters or numbers, all of which are searchable using your filing system or software. After you input these numbers, you can pull up a client record and view purchasing histories, goods and services purchased and specific line-item information. This can be an invaluable help during billing disputes or customer service inquiries.

Why is invoice numbering important in your business?

Numbering your invoices is beneficial to you as well as to your clients or customers. In fact, it’s a vital part of business recordkeeping.

As a freelancer or business owner, invoice numbers are useful for both accounting and payment tracking purposes, especially if you issue multiple invoices each month.

Invoice numbers are helpful for your clients, too. They can reference these numbers in their own internal accounting systems to indicate that particular funds allocated were for a particular purpose, as documented by a particular invoice.

With Acrobat Sign, you can integrate invoices into your workflow as well as collect legal electronic signatures that help you get paid faster.

Find out what else you can do with Acrobat Sign.