Taxpayer registered under GST can apply for refund of excess GST paid in the following cases:

  1. Mistakenly paid excess GST on paying the GST Challan

  2. Mistakenly made payment under wrong head of GST Challan. Eg: amount paid under fee instead of tax

  3. When taxpayer has paid GST on sales and later cancelled the invoice without generating a Credit Note

Read more: Steps to claim GST Refund of excess GST paid on GST Portal