The 15-digit GSTIN is issued by the Goods and Services Tax Network (GSTN), the IT backbone of the proposed tax regime.
"Declaration of valid GSTIN in Customs documents (BE/SB) would be mandatory w.E.F. 0000 hrs of July 1, 2017, the likely implementation date of GST, to avail IGST credit on Imports or GST refund on exports," the revenue department said.
The declared GSTIN would be validated for correct IEC (Import Export Code Number)/PAN linkage.
"All concerned may make use of the special drive by GSTN from June 1 to June 15, 2017 for updation of IEC in GSTIN," the department's advisory said.
More From This Section
Meanwhile, exporters have raised concerns over the tax refund process under the GST.
They are demanding that the current system of ab initio exemption should be continued in the GST also.
Under the GST, exporters will have to first pay the required duty and seek a refund.
As per estimates, exporters' working capital of up to Rs 1.85 lakh crore annually could get struck because of the refund process.