In case of car dealer, the dealer has repaired his own car
standing in fixed assets and has raised bill of Rs 25000 on itself. Thus it was
booked in both expenses and sales. At the time of filling GSTR 1, the portal
denied the entry stating that GSTN of supplier and receiver cannot be same.
Say in another case, I am a furniture trader and want to transfer one sofa set of Rs 40000 to my fixed assets. Here ITC on GST paid on Furniture is allowed. How will I make the entry here also.
The GST is to be charged on supply. The same is defined u/s 7 of CGST Act. It is a transaction in the course of business or furtherance of business for consideration, may be between two different supplier or receiver or between distinct person/ related party. In your case there is no supply because there is no consideration and the transaction is also not covered under clause 2 of Schedule I because it is not between related/ distinct person.
In this case tax was not payable so you should issue credit note against the invoice. But the route of credit note is also not possible because the invoice cannot be uploaded, so the remedy left is to cancel the invoice.
If you want to issue invoice for accounting purpose to make the accounting on the basis of cost center then keep a separate invoice for that or pass a journal voucher to transfer Trading stock to Fixed assets.