How do I change the default Invoice Number?
To change the default format of the invoice number:
- Go to Settings from the top-right corner. 
- Select Invoices under Sales. 
- Enter a Prefix and Next Number under Invoice Number in the General tab. Insight: The **Prefix** that you enter will remain constant. However, the **Next Number** will be incremented by **1** for every subsequent invoice. For example, if your Prefix is INV and your Next Number is 001, this is what your invoice numbers would look like, in order of generation: INV-001, INV-002, INV-003 and so on.
- Click Save. 
Now, the invoices that are generated will follow this format for their invoice numbers.