For accounting practices and tax firms handling dozens of client GSTINs, the Invoice Management System on the GST portal changes monthly compliance from a post-filing check into an active pre-filing decision. Because invoices left unattended in IMS default to deemed acceptance, staff cannot wait until the 19th of the month to begin inward review.
How the IMS mechanism works for practice firms
The GSTN advisory on IMS establishes that recipients can take three distinct actions on inward supplies filed by vendors in GSTR-1, GSTR-1A, or IFF: Accept, Reject, or Pending. Under GSTN revised advisory on IMS, any inward record where no action is taken is treated as deemed accepted when draft GSTR-2B is generated on the 14th of the following month.
Statutory entitlement to credit under Section 16(2)(aa) of the CGST Act requires that supplier invoices be furnished in GSTR-1 and communicated in GSTR-2B. In addition, Section 16(2)(b) of the CGST Act mandates that the recipient must have actually received the underlying goods or services. Deemed acceptance of unverified invoices can cause client books to claim credit on goods not yet received or services never ordered.
Common mistake: Leaving unidentified vendor invoices on No Action status. No Action causes deemed acceptance on the 14th, which draws ineligible credit into GSTR-2B. If this excess credit is subsequently claimed in GSTR-3B without receipt of supply, the taxpayer risks scrutiny and notices under Form DRC-01C pursuant to Rule 88D.
Monthly IMS compliance calendar for 50+ clients
Firms managing multiple clients need batch milestones to prevent junior staff from logging into individual client portals at the last minute. Managing IMS for CA firm multiple clients demands adhering to this operational calendar:
- 12th to 13th of the month (Pre-generation review): Suppliers file monthly GSTR-1 by the 11th. On the 12th, staff download purchase registers from clients and match them against IMS records. Flag mismatch items for client review before draft GSTR-2B generates on the 14th.
- 14th of the month (Draft GSTR-2B generation): The portal generates draft GSTR-2B based on saved actions and deemed acceptances. Verify generated figures against client book balances.
- 15th to 17th of the month (Client sign-off window): Dispatch mismatch sheets to client accountants. Obtain written confirmation for any invoices marked for Reject or Pending status. If the client has not received goods, set the invoice to Pending rather than Reject.
- 18th to 19th of the month (IMS action freezing and re-compute): Submit finalized actions on the IMS dashboard. If actions were updated after the 14th, click re-compute GSTR-2B to pull fresh totals into GSTR-3B.
- 20th of the month (GSTR-3B filing): File GSTR-3B with figures perfectly aligned with recomputed GSTR-2B, eliminating DRC-01C mismatch triggers.
Action decision matrix: Accept, Reject, or Pending
To avoid practice liability, staff should follow a consistent classification protocol across all clients. The table below outlines standard treatment:
| Invoice scenario | Recommended IMS action | Impact on GSTR-2B | Client audit risk |
|---|---|---|---|
| Goods received and matched with books | Accept | ITC included in Table 4(A)(5) | None (compliant claim) |
| Goods in transit or service pending inspection | Pending | Excluded from current 2B | Protects against Section 16(2)(b) breach |
| Duplicate invoice or wrong GSTIN entered by supplier | Reject | Permanently excluded from 2B | Prevents claiming non-existent inward supplies |
| Rate or taxable value mismatch | Pending or Accept with note | Depends on chosen status | Vendor must amend in GSTR-1A or next GSTR-1 |
For invoices kept in Pending status, refer to our operational guide on handling IMS pending invoices for rollover treatment across subsequent tax periods.
Worked example: Multi-client firm reconciliation and re-compute
Consider Mehta and Associates, a firm handling GST filings for client Bright Solar Engineering. For the September 2026 tax period, the client's books show 4 purchase entries, while 5 appear on the IMS dashboard. The total inward tax involved across these 5 invoices is ₹1,62,000.
| Invoice | Supplier | Tax in books | Tax in IMS | Audit status | IMS action |
|---|---|---|---|---|---|
| INV-101 | Alpha Metals | ₹45,000 | ₹45,000 | Goods received in factory | Accept |
| INV-102 | Beta Logistics | ₹18,000 | ₹18,000 | Service completed | Accept |
| INV-103 | Gamma Steel | ₹63,000 | ₹63,000 | Goods in transit (reached Oct 2) | Pending |
| INV-104 | Delta Traders | ₹12,000 | ₹12,000 | Raw materials verified | Accept |
| INV-999 | Zeta Power | ₹0 | ₹24,000 | Wrong GSTIN billed by supplier | Reject |
Calculation of eligible ITC claim:
- Total tax in IMS records: ₹45,000 + ₹18,000 + ₹63,000 + ₹12,000 + ₹24,000 = ₹1,62,000.
- Invoices marked Accepted (INV-101 + INV-102 + INV-104): ₹45,000 + ₹18,000 + ₹12,000 = ₹75,000.
- Invoice marked Pending (INV-103): ₹63,000. This is excluded from September GSTR-2B and held over to October.
- Invoice marked Rejected (INV-999): ₹24,000. This is excluded permanently.
If Mehta and Associates had taken No Action, all five invoices totaling ₹1,62,000 would have been deemed accepted on the 14th. By executing client-approved actions on the 16th and triggering re-compute GSTR-2B on the 18th, the firm legally claimed ₹75,000, preventing an unauthorized claim of ₹87,000 (₹63,000 in transit + ₹24,000 wrong billing).
Client sign-off protocol and audit trail
To shield the tax practice from disputes, never accept or reject doubtful invoices without written client approval. Use a standardized confirmation email for mismatch approvals:
Frequently asked questions
What happens if a CA firm takes no action on client invoices in IMS?
Any invoice left with No Action status is deemed accepted automatically when GSTR-2B generates on the 14th of the following month, pulling that input tax credit into eligible ITC in GSTR-2B and GSTR-3B Table 4(A)(5).
Can an action taken in IMS be changed before filing GSTR-3B?
Yes. A recipient can change an action from rejected to accepted or pending before filing GSTR-3B, but they must click re-compute GSTR-2B on the portal to reflect the updated ITC figures.
Does an invoice kept pending in IMS expire immediately?
No. Invoices marked as Pending remain on the IMS dashboard until they are accepted, rejected, or until the time limit under Section 16(4) expires.
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Last checked: 26 October 2026. Sources: GSTN IMS FAQs, GSTN Revised Advisory on IMS, CBIC Section 16 CGST Act.