GST State code in Sales and Purchase Invoice

We are selling products in many states with different GST number in each state. Sales invoices followed simple numbering scheme irrespective of the state in which the sale was made. Our accounts team recently came back to us with a request to incorporate GST state code in the sales and purchase invoice for easy GST return filing. The issue they faced to provide invoice series range for GST tax input credits.

e.g. consider we have following invoices
SINV-0001 - GST state Maharashtra
SINV-0002 - GST state delhi
SINV-0003 - GST state maharashtra
SINV-0004 - GST state delhi

while filing GST return we were not able to specify invoice rage like SINV-0001 to SINV0004 since they do not belong to one state.

The feature we are planning to add is to incorporate GST state code in the invoice numbering so above invoices would be numbered like -

SINV-27-0001 - GST state Maharashtra
SINV-07-0001 -GST state delhi
SINV-27-0002 - GST state maharashtra
SINV-07-0002 - GST state delhi

So it would be easier to specify the range as SINV-27-0001 to SINV-27-0002

Any inputs/suggestions on above approach. Can this be contributed to the code in the form of new keyword for naming series ?

Why is this needed if you can filter gst sales register report by GSTIN?

@Pawan our accounts team wanted this because it is impractical for them to put individual sales invoice numbers on GST portal while filing returns. Our accounts team mentioned that they specify range of the invoice instead e.g. invoice number 0001 to 0100. However since there are many invoices in between which are of different state they have to show them as cancelled.

Is there any better way to export GST sales register to GST portal?

If you are just planning to create a number series for different states then that can be created by users as per their requirement. Don’t think it should be part of core then.

However, if you are planning to automate series selection based on some conditions, then maybe you could consider contributing it. You can also, explore integration with any GSP for complete automation & contribute it.