Most IGST refund delays are caused by data mismatch, not legal ineligibility. Validate invoice, shipping bill, and return data before filing.
Reconcile GSTR-1 with shipping bill data line by line. HSN, invoice number format, and taxable value variances are common blockers.
Track ICEGATE and GST portal acknowledgement states together. A claim can appear complete in one system while pending due to validation failure in another.
If a rejection occurs, treat rectification as a mini-project with documented correction logs and re-submission notes.