Debitoor Dictionary

Accounting terms explained in a simple way

Over 150 Articles for Founders and Entrepreneurs

  1. Invoice
  2. Accounting year
  3. Credit note

Invoice number - What is an invoice number?

The unique number that is systematically assigned to each invoice

Easily keep track of your invoices with automated invoicing and accounting software such as Debitoor. Try it free for 7 days.

Invoice numbers are necessary to ensure proper documentation of charges and income. The number should be present on each invoice issued, and should be numbered sequentially.

It is a unique code that allows easy identification of each invoice created and issued and provides a simple way to keep track of each payment due from a customer.

If you are just starting out, your first invoice to a customer will have a variation of the invoice number ‘1’. The next will have ‘2’, etc. The invoice number continues to progress regardless of the client. It is the running total of invoices for your business.

Assigning invoice numbers

New businesses may not have high numbers of invoices to begin with, but it is important to consider future growth when choosing an effective invoice numbering system.

Instead of numbering invoices ‘1’, ‘2’, etc., organisation can be improved by also including the year the invoice was issued, or the month if preferred, while allowing room for the creation of new invoices in the coming fiscal year.

For example: for the first invoice in 2016, the invoice could be ‘160001’. The next invoice would then be ‘160002’ etc.

This system allows you to quickly see which year an invoice is issued and still follows the sequential numbering requirement. Including the year in your invoice number improves organisation at the end of the fiscal year and prevents confusion or the necessity to search through invoices to determine which year they were issued.

Choose the numbering system that works best for your business and be sure to include an updated invoice number on each invoice you send out.

Sample of an invoice number on an invoice created using a Debitoor invoice template

Deleting invoices

There are very few reasons that an invoice should be deleted. Because invoices are numbered sequentially, an invoice that has been completed in your records and is then deleted could show up as a gap in your financial records.

Often it is better to create a credit note for that invoice instead, if you wish to remove that amount. You should be very certain about deleting an invoice before you choose to do so.

Invoice numbers with Debitoor

Invoicing and accounting software such as Debitoor automatically keeps track of your invoice numbers. The invoice templates have a built-in section for invoice numbers and automatically include it on each new invoice.

To enter a preferred numbering method, simply type it into the ‘Invoice No.’ box and each new invoice will automatically be updated to the following sequential number.

There’s no need to worry about keep track of which number you’re on, and all invoices are easily searchable by number, customer name, date, and can be filtered by payment status.