4.52 Invoice Numbering
Navigate to System >> Invoice Templates
Scroll down and you would see Invoice Number Prefix and Next available invoice no
Fig 14.0 shows the invoice numbering
The invoice number prefix can be set if you have a prefix. For eg If your invoice number is INV2204, enter INV in the Invoice Number Prefix field.
The next available number is used to enter your next available invoice number.
Please note that this is a one time setting.