In Halaxy, an invoice number is automatically assigned when you create an Invoice. However, you have the option of creating your own custom numbering. This allows you to keep track of your invoices based on your personal preferences or to keep your invoices consistent if you have imported them from another practice management software package.
To set up custom invoice numbering:
Click Settings > Payments.
In the Invoice Numbering section, click Edit.
The Edit Invoice Number Settings pop-up appears. Select "Custom invoice numbering".
You can optionally add a prefix and suffix and choose the next available invoice number. An example invoice number is shown below.
RESULT: New invoices will follow your new numbering. Note that previously created invoices will still have their old numbers. To change the invoice number of an existing invoice, see the Invoice Summary by clicking the cogwheel icon on any invoice.