Practical GST Guide

IMS under GST: Complete Invoice Management System Guide

Understand how the Invoice Management System works, what to accept, reject or keep pending, how IMS affects GSTR-2B and GSTR-3B, and how an accounts team can operate the process every month without losing or wrongly claiming ITC.

IMSReview supplier-reported records
GSTR-2BUse the resulting ITC statement
GSTR-3BTake eligible ITC after legal review

1. What is IMS under GST?

Invoice Management System (IMS) is a GST portal facility through which a recipient can review records reported by suppliers in their outward-supply returns and take an action on those records before the recipient finalises the related GSTR-3B.

The key purpose is not simply to create another report. IMS gives the recipient a structured way to communicate how supplier-reported records should be treated for the recipient's ITC workflow.

Remember: IMS and GSTR-2B are not the same. IMS is the action/review layer; GSTR-2B is the system-generated ITC statement. Your accounting team should use IMS actions together with books, invoice documents and the GST law—not treat an IMS status alone as proof that ITC is legally eligible.

GSTN introduced IMS from the GSTR-2B return period of October 2024. The first draft GSTR-2B based on IMS actions was generated for October 2024 on 14 November 2024.

2. Why IMS is important for accounts teams

Before IMS, the recipient generally discovered supplier mismatches while reconciling purchase records with GSTR-2B. IMS adds an earlier operational layer where the recipient can identify records that should not be treated as accepted, or should be kept pending until the issue is resolved.

  • It helps identify invoices that do not belong to the recipient.
  • It helps manage supplier errors before ITC is finally considered.
  • It provides a process for dealing with amendments and credit notes.
  • It affects what appears in the recipient's draft/recomputed GSTR-2B for the relevant period.
  • It gives the purchase/accounts team a defined review point before GSTR-3B.
Important: Do not make “accept everything” the default internal policy merely because no action is deemed accepted for GSTR-2B generation. A no-action record can still be wrong, duplicated, unrelated to the business or legally ineligible.

3. The complete IMS → GSTR-2B → GSTR-3B flow

Supplier reports
GSTR-1 / 1A / IFF
Record appears
in recipient IMS
Recipient reviews
invoice & evidence
Accept / Reject / Pending / No Action
GSTR-2B is generated or recomputed
Eligible ITC is reviewed for GSTR-3B

GSTN states that supplier records reported through GSTR-1/1A/IFF populate the recipient's IMS for action. At GSTR-2B generation, accepted records form part of the available ITC flow, rejected records are excluded, and pending records are carried in IMS rather than included for that month's GSTR-2B. No-action records are treated as deemed accepted at GSTR-2B generation.

Practical rule: The correct sequence for an accounts team is supplier data → IMS review → books reconciliation → ITC eligibility review → GSTR-2B → GSTR-3B. Do not reverse this into “GSTR-2B amount = automatic ITC”.

4. What do Accept, Reject, Pending and No Action mean?

IMS statusPractical meaningEffect on GSTR-2BWhat the team should do
AcceptThe recipient accepts the supplier-reported record.Accepted records can form part of GSTR-2B ITC available, subject to the applicable rules and system treatment.Accept only after reasonable verification of supplier, invoice, receipt/service and tax details.
RejectThe record does not pertain to the recipient or is materially erroneous and cannot appropriately be handled by a credit/debit note or correction.Rejected records are not considered for GSTR-2B generation.Use carefully. Keep evidence and reason for rejection.
PendingThe recipient needs more time or clarification before deciding.Pending records are not considered for that month's GSTR-2B and remain in IMS for later action.Use as an exception queue, not as a permanent parking area.
No ActionNo action has been taken by the recipient.No-action records are treated as deemed accepted when GSTR-2B is generated.Do not rely on no action as a substitute for reconciliation.

These effects are described in GSTN's IMS advisory and FAQs.

5. When should an invoice be rejected?

GSTN specifically cautions that rejection should be done carefully because a rejected invoice will not provide ITC to the recipient through the IMS-driven GSTR-2B flow. GSTN identifies a record as a candidate for rejection where it does not pertain to the recipient, or where the error is so significant that the situation cannot appropriately be handled through a credit/debit note.

Good candidates for rejection

  • Invoice belongs to a different GSTIN of the same group.
  • Supplier has incorrectly reported your GSTIN and the transaction is not yours.
  • Completely fictitious or duplicate invoice with no underlying supply.
  • Material reporting error where the record cannot reasonably be corrected through the appropriate supplier document.

Do not reject merely because

  • Invoice number has a minor formatting difference that can be reconciled.
  • Books have not yet been updated even though the purchase is genuine.
  • Goods/service receipt confirmation is pending and your internal process needs more time.
  • Taxable value differs slightly and the supplier can issue an appropriate correction/document.
High-risk mistake: Do not reject an invoice simply to remove a mismatch from the reconciliation report. Rejection can prevent the related ITC from flowing into GSTR-2B. First determine whether the problem is a genuine non-recipient transaction, a supplier amendment issue, a timing issue, a book-posting issue or an eligibility issue.

6. How should Pending be used?

Pending is useful when the recipient cannot responsibly accept or reject a record yet. For example, the purchase department may need to confirm whether the material was actually received, or the vendor may need to clarify an incorrect GSTIN, invoice number or taxable value.

GSTN states that pending records are not considered for GSTR-2B for that month and remain in IMS for further action in subsequent months.

But Pending is not available in every situation

GSTN identifies restrictions for certain credit-note and amendment scenarios, including original credit notes, certain upward credit-note amendments, certain downward credit-note amendments, and certain downward invoice/debit-note amendments where the original was accepted and the relevant GSTR-3B has already been filed.

7. What happens if you change an IMS action after GSTR-2B is generated?

The process does not necessarily end on the 14th. GSTN states that the recipient can continue to take action on records after GSTR-2B generation and, where required, recompute GSTR-2B before filing the relevant GSTR-3B. After filing GSTR-3B for the period, further action for that month's IMS records is not available.

  1. GSTR-2B is generated.
  2. An invoice is later identified as wrongly accepted/no-action.
  3. The recipient takes the appropriate IMS action.
  4. The recipient recomputes the relevant GSTR-2B.
  5. The updated GSTR-2B is used in the remaining GSTR-3B review.
Operational control: Your monthly close should have a defined cut-off before GSTR-3B filing. The person who changes IMS actions should communicate the change to the person preparing the ITC working.

8. Amendments, credit notes and debit notes

IMS becomes particularly important when the supplier changes a document. The team should not treat every amendment as a new independent invoice. Always identify the original document and determine what changed.

SituationWhat to checkPractical response
Invoice amendmentOriginal vs revised GSTIN, invoice number, date, value, tax, POS.Identify whether the amendment corrects the existing transaction or creates a material mismatch.
Debit noteUnderlying supply and additional tax.Verify commercial document and tax impact before accepting.
Credit noteWhether the underlying purchase/ITC was already reversed or adjusted.Do not ignore the ITC reduction merely because the original invoice was previously reconciled.
Incorrectly rejected invoiceWhether it is genuinely your invoice and legally eligible.GSTN says it can be accepted again in IMS before filing GSTR-3B, followed by recomputation of GSTR-2B.

GSTN's October 2024 additional FAQ specifically explains that an erroneously rejected invoice can be accepted again before GSTR-3B filing and the updated GSTR-2B recomputed.

9. Not every GSTR-2B record comes through IMS

This is one of the most important concepts for users working with IMS and GSTR-2B.

GSTN's IMS FAQ states that certain records are not made available in IMS but can directly flow to GSTR-2B. These include documents flowing from GSTR-5 and GSTR-6, ICEGATE documents, RCM records, specified documents where ITC is ineligible due to place-of-supply or section 16(4) restrictions, and documents subject to Rule 37A reversal treatment.

Therefore: “IMS has no invoice” does not automatically mean “GSTR-2B will have no corresponding record.” Your GSTR-2B reconciliation must also cover imports, ISD, RCM and other system-generated categories.

10. Practical monthly IMS working procedure

Step 1 — Download your purchase register

Close the purchase register for the period as far as practicable. Keep supplier GSTIN, invoice number, invoice date, taxable value, IGST, CGST, SGST/UTGST, cess, purchase type, project/location and booking status.

Step 2 — Open IMS and identify exceptions

Do not begin by accepting everything. First identify invoices that are clearly unrelated, duplicated, materially incorrect or awaiting business confirmation.

Step 3 — Match IMS records with books

Use at least supplier GSTIN + invoice number as the primary key, with invoice date and tax values as secondary controls.

Step 4 — Investigate exceptions

ExceptionLikely reasonAction
IMS invoice, not in booksLate booking / unrecorded purchase / wrong GSTINCheck PO, GRN, invoice and site records before deciding.
Books invoice, not in IMSSupplier has not filed / filing missed cut-off / wrong GSTINFollow up with supplier and track next GSTR-2B.
Tax value mismatchSupplier reporting error / debit-credit note / book errorCompare source invoice and supplier filing; do not blindly reject.
DuplicateDuplicate invoice or duplicate bookingVerify underlying supply and accounting entries.
Wrong GSTINSupplier selected another registrationAsk supplier to correct; reject only after confirming it is not your transaction/appropriate correction route.

Step 5 — Decide IMS action

Use Accept, Reject or Pending based on evidence. Understand that no action is treated as deemed accepted for GSTR-2B generation.

Step 6 — Reconcile GSTR-2B

After generation, download GSTR-2B and reconcile it to the final purchase register. Include ISD, RCM and import categories separately.

Step 7 — Perform legal ITC review

Check section 16 conditions, blocked credits, time limits, business-use requirements, reversals and other applicable provisions. GSTR-2B is not a substitute for the recipient's legal eligibility review.

Step 8 — Prepare GSTR-3B

Use the eligible ITC after reconciliation and legal review. GSTN states that specified GSTR-2B values feed the relevant GSTR-3B ITC fields, while the taxpayer remains responsible for reviewing and correcting the return where required.

11. Practical examples

Example 1 — Invoice belongs to another GSTIN

A group has GSTIN-A and GSTIN-B. Supplier accidentally reports a ₹2,00,000 invoice against GSTIN-A, but the goods were purchased and received by GSTIN-B.

Correct approach: GSTIN-A should not claim ITC merely because the invoice appears. Investigate and have the supplier correct the reporting. If the record genuinely does not pertain to GSTIN-A, rejection may be appropriate after internal verification.

Example 2 — Genuine invoice not booked yet

Supplier reports an invoice in IMS, but the accounts team has not received the invoice from the site.

Do not automatically reject. Check GRN, PO, delivery proof and site records. If the purchase is genuine but documentation is pending, use the appropriate workflow and keep an audit trail.

Example 3 — Wrongly rejected genuine invoice

An employee rejects a genuine invoice by mistake. Before filing GSTR-3B, the team identifies the error.

GSTN guidance: the recipient can accept the invoice again in IMS and recompute the relevant GSTR-2B before filing GSTR-3B.

Example 4 — Supplier files after the cut-off

The supplier files its document after the relevant GSTR-2B cut-off. The invoice may not appear in the expected month's GSTR-2B.

Correct approach: do not conclude that the supplier has not filed solely from one month's GSTR-2B. Check the supplier filing period and the next open GSTR-2B. GSTN explains that supplier-filed documents flow into the next open GSTR-2B based on the applicable cut-off.

12. Recommended IMS + GSTR-2B reconciliation format

FieldPurpose
Supplier GSTINPrimary supplier identification
Supplier nameCommercial verification
Invoice / document numberPrimary document matching key
Invoice dateDate and period control
Taxable valueValue reconciliation
IGST / CGST / SGST / CessTax reconciliation
Books statusBooked / not booked / duplicate / error
IMS statusAccepted / rejected / pending / no action
GSTR-2B statusAvailable / not available / reversal / ineligible
ITC eligibilityEligible / ineligible / partial / pending review
Reason / actionSupplier follow-up and audit trail
Owner & follow-up dateException management
Best practice: Keep IMS status and ITC eligibility as separate columns. An invoice can be accepted in IMS but still require a separate legal eligibility assessment.

13. Internal financial controls for IMS

  • Maintain a documented monthly IMS review owner for each GSTIN.
  • Do not permit blanket rejection of invoices without supporting reason.
  • Require purchase/site confirmation for disputed invoices.
  • Maintain a rejected/pending exception register.
  • Track supplier corrections and the month in which the corrected record is expected.
  • Perform a final IMS review before GSTR-3B preparation.
  • Document all post-GSTR-2B recomputations and their impact on the ITC working.
  • Reconcile GSTR-2B separately for B2B, ISD, RCM and imports.
  • Maintain evidence for high-value ITC: invoice, PO, GRN/service proof, payment records where relevant and accounting entry.
  • Have a second-level review for unusual rejection, large ITC reversals and major month-on-month changes.

14. Common IMS mistakes

  1. Accepting everything automatically: No action is deemed accepted for GSTR-2B generation, but that does not make every invoice legally eligible.
  2. Rejecting to make reconciliation look clean: A rejection can remove the ITC flow. Resolve the underlying issue instead.
  3. Ignoring pending records: Pending is a temporary exception state and should have an owner and follow-up date.
  4. Not recomputing GSTR-2B: If an IMS action changes after initial generation, check whether recomputation is required before GSTR-3B.
  5. Ignoring records outside IMS: Imports, ISD, RCM and other specified records require separate review.
  6. Treating GSTR-2B as final legal eligibility: Other ITC restrictions still need self-assessment.
  7. Not preserving an audit trail: Keep evidence for why a record was accepted, rejected or kept pending.

15. Frequently Asked Questions

Is IMS mandatory?

GSTN's October 2024 additional FAQ states that taking action on IMS records is not mandatory for GSTR-2B generation; records with no action are treated as accepted for generation. However, an organisation may still need an internal review process to prevent wrong ITC.

What happens if I take no action in IMS?

No-action records are treated as deemed accepted when GSTR-2B is generated.

Can I reject a genuine invoice by mistake and correct it?

GSTN states that an erroneously rejected invoice can be accepted again before filing GSTR-3B, followed by recomputation of the updated GSTR-2B.

Can I take action after GSTR-2B is generated?

Yes. GSTN states that recipients can take action after the 14th and recompute GSTR-2B until the relevant GSTR-3B is filed.

Does every GSTR-2B invoice appear in IMS?

No. GSTN lists several categories that do not appear in IMS but can directly flow to GSTR-2B, including specified GSTR-5/GSTR-6 records, ICEGATE documents and RCM records.

Does acceptance in IMS mean ITC is automatically eligible?

No. IMS status is not a replacement for the recipient's legal ITC eligibility assessment. GSTN specifically cautions that there can be other situations where ITC is not available and the taxpayer must self-assess and reverse or restrict such credit in GSTR-3B.

Can I edit GSTR-2B itself?

No. GSTR-2B is a read-only static statement. Errors or omissions should be addressed through supplier correction, IMS action where applicable, reconciliation and the relevant return process.

Should Pending be used for every mismatch?

No. Pending is a useful exception status, but GSTN restricts pending action for specified credit-note and amendment situations.

What should I do when an invoice is in books but not in IMS?

Check supplier filing status, reporting period, cut-off timing, GSTIN and document details. Track the invoice for the next applicable GSTR-2B rather than assuming it is permanently missing.

What is the best way to use IMS in a large company?

Use IMS as an exception-management workflow connected to purchase register reconciliation. Assign invoice review to the purchase/accounts owner, escalation to the tax team and final ITC review to the responsible GST return preparer.

16. GSTN references and related reading

For the legal framework and section-wise explanations, use the GST Act Section Wise Guide on this website.

How to use this guide: First understand the IMS action, then reconcile the document with books, then determine ITC eligibility and finally prepare GSTR-3B. The portal's system treatment and applicable GST law should always be checked for the relevant tax period.