Why GSTR-1 and GSTR-3B should agree
GSTR-1 reports outward supplies invoice by invoice; GSTR-3B is the summary return through which tax is actually paid. Over a year, the tax on taxable outward supplies in both should broadly match. The tool shows the difference as GSTR-3B minus GSTR-1 for each head, so a negative number means less was reported (and paid) in GSTR-3B.
Common reasons for differences
- Amendments: invoices amended in a later month’s GSTR-1 while GSTR-3B was corrected in a different month.
- Credit and debit notes: netted in GSTR-3B but reported separately in GSTR-1, or reported in different months.
- Advances: tax paid on advances in GSTR-3B and adjusted later.
- Timing: an invoice missed in one month’s GSTR-1 and added the next month.
- Nil-rated and exempt supplies: shown separately in GSTR-3B Table 3.1(c), not in 3.1(a).
- Zero-rated supplies: exports and SEZ supplies go to Table 3.1(b), not 3.1(a).
Example (illustrative)
A Morbi ceramics unit enters its first quarter. In May, GSTR-1 shows IGST ₹45,000 but GSTR-3B shows ₹43,200; the row turns red with a −₹1,800 difference. The accountant finds an invoice added to GSTR-1 late, and pays the difference with interest. In June, GSTR-3B is higher because a June invoice was paid in 3B but reported in July’s GSTR-1.
Common mistake
Comparing the total of GSTR-3B Table 3.1 with GSTR-1 including exports and exempt supplies. Compare like with like: Table 3.1(a) against taxable domestic outward supplies in GSTR-1, after credit/debit notes and amendments.
About DRC-01B
The GST portal issues an intimation in Form DRC-01B where the liability declared in GSTR-1 is higher than the tax paid in GSTR-3B beyond a limit. You respond by paying the difference or explaining it. The limit and procedure can change, so check the latest position on the GST portal.