It is very common that customers of e-commerce companies return goods. How these returns are going to be adjusted

  1. An e-commerce company is required to collect tax only on the net value of taxable supplies.
  2. In other words, the value of supplies which are returned are adjusted in the
    aggregate value of taxable supplies. (Refer to Explanation to Sec. 52(1) of the CGST Act, 2017).

(FAQ 8: E-COMMERCE)