Users can manually create their own number series by typing the proforma invoice number in the Invoice #. 

1. Click on Proforma Invoice 
2. Click on the ‘+’ sign to generate a new proforma invoice
3. Manually add proforma invoice number in proforma  invoice #, e.g. Moon Proforma 1
4. Enter other invoice details and click on ‘Save.’

After creating a proforma invoice series, all the upcoming invoices will be saved in the succeeding number—for example, Moon Proforma 2, Moon Proforma 3, and so on.