In cases where the exporter has filed correct information in the GST returns and it gets successfully validated by the GSTN, it is thereafter transmitted electronically to the Customs system wherein the GST return data is matched with the shipping bill data. If the matching is successful, ICES processes the claim for refund and the relevant amount of IGST paid with respect to each shipping bill or bill of export is electronically credited to the exporter’s bank account as registered with the Customs authorities. But, wherever the matching fails on account of some error, the refund does not get sanctioned. The matching between the two data sources is done at the invoice level and any mismatch of the laid down parameters results in one or more of the following errors/responses:
| Code | Meaning |
| SB000 | Successfully validated |
| SB001 | Invalid SB details |
| SB 002 | EGM not filed |
| SB 003 | GSTIN mismatch |
| SB004 | Record already received and validated |
| SB005 | Invalid invoice number |
| SB006 | Gateway EGM not available |
| PFMS VALIDATION ERROR | Bank Account details of the exporter not validated in PFMS |