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A DRC-01B intimation lands on the common portal on the morning of the twenty-second, the day after the twenty-first-onwards monthly GSTR-3B validation window. It reads that the outward tax liability declared in the enterprise's own GSTR-1 for the previous tax period exceeded the tax paid through the corresponding GSTR-3B by more than the Rule 88C threshold. The seven-day reply clock is already running. Three parallel questions land on the tax analyst's screen at the same time. What is the actual root cause of the differential — a credit note timing drift, a Section 51 TDS misclassification, a genuine short-payment, or a data-entry error? What is the right reply option — voluntary payment through DRC-03, a Part B rebuttal, or a hybrid accept-and-dispute? Who signs the reply, and what working paper does the sign-off rest on? A triage that is not sequenced across the first 72 hours risks a rushed reply on Day 6 or Day 7 that either overpays the differential or forecloses the amendment pathway.
Sequence the response as a four-block, 72-hour cadence with named owners and a working paper produced at each block. Hour 1 — portal capture: download the DRC-01B PDF, screenshot the portal state, notify the tax analyst, tax manager, and controller within fifteen minutes, and open a triage folder in the working paper archive. Hours 2 to 24 — root cause: pull the GSTR-1 and GSTR-3B for the notice period, reconcile Table 3.1 outward and Table 6.2 TDS lines against the internal register, and isolate the differential into one of five buckets. Hours 24 to 48 — reply drafting: draft one of Option A (DRC-03 with Section 50 interest), Option B (Part B rebuttal with working paper), or Option C (hybrid accept-and-dispute), and computing Section 50 interest at up to eighteen per cent per annum from the original due date. Hours 48 to 72 — sign-off ceremony: controller reviews the draft against the working paper, DRC-03 is generated if Option A or C, Part B is filed on the portal, acknowledgement reference number is archived, and the failure mode is logged for the next Day 17 reconciliation.
A triage kickoff checklist that opens on Hour 1 — DRC-01B PDF download, portal screenshot, calendar block for Hours 2 to 24 root cause session, notification to tax analyst, tax manager, and controller. A GSTR-1 versus GSTR-3B reconciliation template pre-populated for the notice tax period. A five-bucket variance classification — credit note timing, Section 51 TDS misclassification, amendment window items, data-entry error, genuine short-payment. A Section 50 interest calculator that takes the differential amount, the original due date of the GSTR-3B, and the intended DRC-03 payment date and returns the interest at up to eighteen per cent per annum. A DRC-03 generation checklist and a Part B reply template for each of the three options. A sign-off log for the controller review that captures the working paper reference, the option chosen, and the acknowledgement reference number returned by the portal.
By the end of Hour 72, the DRC-01B is closed on the portal with an acknowledgement reference number archived in the monthly working paper folder. The DRC-03 challan reference is filed alongside the reply if Option A or Option C was chosen, and the Section 50 interest computation is preserved for future audit sampling. The Part B reply is filed with the reconciliation working paper attached if Option B or Option C was chosen, and the working paper is signed by the tax manager and countersigned by the controller. The failure mode that produced the mismatch is logged in the reconciliation process design register so the next Day 17 reconciliation catches the class before another DRC-01B fires. The exposure to Section 73 assessment is closed for Option A; for Option B or Option C, the working paper is the primary defence against a future Section 74 characterisation.
I opened the GSTN portal at nine in the morning on the twenty-second and there it was — a fresh DRC-01B Part A intimation for last month’s tax period. The tax payable declared in our own GSTR-1 had exceeded what we had paid through GSTR-3B by more than the Rule 88C threshold, and the portal was politely giving me seven days to either pay the differential through DRC-03 or file a Part B reply explaining why the apparent mismatch was not an actual liability shortfall. This is the playbook I run in the first 72 hours — before the seven-day clock forces a rushed decision on Day 6, and before the residual becomes a Section 73 or Section 74 assessment matter.
The Days 16 to 20 GSTR-1 versus GSTR-3B runbook is the preventive discipline that keeps DRC-01B from firing in the first place. This triage playbook is the recovery discipline when Day 17 slipped and the portal validation caught what our monthly close did not.
Why the first 72 hours decide the case
Rule 88C of the CGST Rules was inserted by Notification 26/2022-Central Tax dated 26 December 2022. It created a pre-adjudication intimation regime — where the GSTR-1 declared liability exceeds the GSTR-3B tax paid for a tax period by the amount and percentage recommended by the Council, the intimation is served in Part A of Form GST DRC-01B on the common portal. The registered person then has seven days to either pay the differential through DRC-03 with Section 50 interest, or furnish a reply in Part B explaining why the differential is not an actual shortfall.
The seven-day window is a hard clock. It runs from the date of intimation on the portal — not from the date the finance team logs in and reads it. If Monday morning brings a DRC-01B, the reply is due by end of the following Monday. The reply is filed on the same portal path where the mismatch was first declared — Services → Returns → DRC-01B — with the acknowledgement reference number generated on submission as the sole proof of timely reply.
Seventy-two hours is the sensible planning window inside the seven days. It gives the tax analyst time to reconcile the root cause without a rushed shortcut, the tax manager time to review the working paper, and the controller time to sign off on the reply option without being handed a fait accompli at 6pm on Day 6. It also leaves a 96-hour buffer for a portal issue, a challan-side ledger lag, or a last-minute correction to be handled without breaching the seven-day statutory window.
Hour 1 — portal capture and workflow assignment
The first hour is not about diagnosis. It is about capture. Three things must be done in the first 60 minutes.
Download the DRC-01B PDF from the portal. The Part A intimation is available as a printable PDF on the Services → Returns → DRC-01B path. Save the PDF with a filename that includes the GSTIN, the tax period, and the intimation date — for example, DRC-01B_29ABCDE1234F1Z5_202506_2026-08-22.pdf. File it in a fresh triage folder inside the monthly working paper archive.
Screenshot the portal state. The intimation reference number, the differential amount, the applicable tax heads (IGST, CGST, SGST, Cess), and the reply-by date must all be captured in a portal screenshot as the intimation appears on the day it was received. Portal displays can change over the seven-day window as replies are filed against them; the screenshot is the contemporaneous evidence.
Notify and assign within fifteen minutes. The tax analyst who will run Hours 2 to 24 must be on the calendar for the next working day. The tax manager who will run Hours 24 to 48 must be on the calendar for the day after. The controller who will sign off Hours 48 to 72 must be on the calendar for the third day. An email to all three, referencing the intimation, the differential amount, and the reply-by date, opens the triage workflow. Without the fifteen-minute assignment, the triage silently defaults to a single-person job that will slide past Day 3.
The Hour 1 output is a triage folder with the DRC-01B PDF, the portal screenshot, and a calendar block on each of the three subsequent working days. No diagnosis has happened yet. That begins at Hour 2.
Hours 2 to 24 — root cause and the illustrative Rs 1,15,000 case
The tax analyst opens the working paper session at Hour 2 with two inputs — the GSTR-1 as filed for the notice tax period and the GSTR-3B as filed for the same period. Both are downloadable from the portal in JSON, and the portal-supplied offline utility converts them to Excel.
The reconciliation walks Table 3.1 of GSTR-3B against the Table 4, 5, 6A, 6B, and 6C aggregates of GSTR-1 matched to tax head (IGST, CGST, SGST, Cess), and walks Table 6.2 of GSTR-3B against the GSTR-7A downloads from every government-deductor customer and GSTR-8A downloads from every e-commerce operator. The differential the portal has computed is reconciled against the internal computation, and the source is isolated into one of five buckets.
The intimation on my desk this morning showed a GSTR-1 declared liability of Rs 12,60,000 against a GSTR-3B tax paid of Rs 11,45,000 — a differential of Rs 1,15,000 across IGST and CGST-SGST heads combined. The Hour 2 to Hour 24 reconciliation walks the Rs 1,15,000 into one of the following classifications.
Credit note timing drift. A Section 34 credit note issued in the current tax period against an invoice raised in the notice tax period reduced the GSTR-3B liability but has not yet flowed into the Table 9B amendment of a subsequent GSTR-1. The Part B reply attaches the credit note and cites Section 34.
Section 51 or Section 52 TDS or TCS misclassification. A Section 51 GST TDS credit at the two per cent rate was booked into Table 6.2 of GSTR-3B as an offset to output liability but the corresponding GSTR-7A had not filed at the time of GSTR-3B submission. The Part B reply attaches the deductor’s GSTR-7A confirmation.
Section 39(9) amendment already filed. A Table 9A, 9B, or 9C amendment in a subsequent GSTR-1 has already corrected the GSTR-1 side of the mismatch. The reply attaches the amendment table extract and cites Section 39(9) — the amendment window closes on 30 November following the end of the financial year to which the details pertain.
Data-entry error. A B2C invoice was declared as B2B in GSTR-1 (or vice versa), a place-of-supply misclassification split the tax head between IGST and CGST-SGST incorrectly, or a rate error inflated one side. The Part B reply attaches the invoice register extract and cites the amendment that has been filed (or will be filed) in the next GSTR-1.
Genuine short-payment. No credit note, no TDS-offset, no amendment, no data-entry error — the GSTR-3B was simply filed short of the GSTR-1 declared liability. The reply option is DRC-03 with Section 50 interest; there is no Part B rebuttal to make.
On the Rs 1,15,000 case, the working paper closed at Hour 20 with the differential split as Rs 68,000 to a credit note that had not yet flowed into a Table 9B amendment (Bucket 1), Rs 27,000 to a Section 51 TDS credit whose GSTR-7A had filed late (Bucket 2), and Rs 20,000 to a genuine data-entry error where an SGST line had been entered as an IGST line (Bucket 4). No short-payment component. This maps to a hybrid Option C reply — Rs 20,000 accepted via DRC-03 with Section 50 interest, Rs 95,000 rebutted in Part B with the credit note and GSTR-7A attached.
The GSTR-1 versus GSTR-3B reconciliation failure modes article catalogues the twelve underlying failure classes that produce every DRC-01B intimation on a bona fide taxpayer — the five buckets above are the operational grouping the triage uses to route each row to the right reply option.
Hours 24 to 48 — reply drafting and the three options
Hour 24 opens with the reconciliation working paper on the tax manager’s screen. The next 24 hours produce the draft reply.
Option A — accept and pay via DRC-03. The differential is discharged as a voluntary payment through Form GST DRC-03 on the portal, generated against the DRC-01B intimation reference number for the same GSTIN and tax period. Section 50 interest is self-computed at up to eighteen per cent per annum from the original GSTR-3B due date (the twentieth of the month following the tax period) to the DRC-03 payment date and paid alongside the tax through the same challan. On a Rs 20,000 differential discharged 45 days after the original due date, the Section 50 interest is Rs 20,000 multiplied by eighteen per cent multiplied by 45 divided by 365 — approximately Rs 444 — payable from the electronic cash ledger. The Part B reply then cites the DRC-03 reference as the closure evidence.
Option A carries the cleanest exposure profile. A voluntarily paid differential with Section 50 interest attracts no penalty under Section 73 or Section 74 — the penalty triggers only where the shortfall is confirmed in adjudication. A paid-and-explained DRC-01B is closed for good.
Option B — dispute the differential in Part B. The reply is filed in Part B of DRC-01B on the portal with the reconciliation working paper attached as supporting documentation. No DRC-03 is generated. The reply cites the specific bucket and attaches the credit note or GSTR-7A or Table 9A/9B/9C extract as evidence.
Option B carries a residual exposure. If the CBIC’s proper officer later disagrees, the case moves to a Section 73 show cause notice (three-year window from the annual return due date, penalty ten per cent of the tax or Rs 10,000 whichever is higher) or, if intent is alleged, a Section 74 notice (five-year window, penalty one hundred per cent of the tax or Rs 10,000 whichever is higher). The working paper attached to the Part B reply is the primary evidentiary defence against a Section 74 characterisation — a contemporaneous reconciliation signed by the tax manager and countersigned by the controller is what distinguishes a bona fide reconciliation difference from wilful mis-statement.
Option C — hybrid accept-and-dispute. The Hours 2 to 24 buckets split the differential into an accepted portion (a genuine short-payment or a confirmed data-entry error) and a disputed portion (the credit note, TDS, or amendment items). A DRC-03 is generated for the accepted portion with Section 50 interest; the Part B reply cites the DRC-03 reference for the accepted portion and attaches the reconciliation working paper for the disputed portion. On the Rs 1,15,000 case above, Option C was what the working paper directed — Rs 20,000 through DRC-03 (approximately Rs 444 interest) and Rs 95,000 in Part B with the credit note and GSTR-7A attached.
The Hour 24 to Hour 48 output is the drafted reply text, the drafted DRC-03 challan (if applicable), the drafted Part B narrative, and the reconciliation working paper laid out for controller review. Nothing is submitted to the portal yet — that is Hour 48 to Hour 72.
Hours 48 to 72 — sign-off ceremony and portal submission
The controller opens Hour 48 with three items on the desk: the DRC-01B intimation, the reconciliation working paper, and the drafted reply. The next 24 hours are the sign-off ceremony.
Working paper review. Every line on the reconciliation is traced back to source — the credit note is opened, the GSTR-7A is opened, the amendment table extract is opened. The classification of each bucket and the choice of Option A, B, or C is confirmed against the paper. This is the review a Section 74 assessment years later will read against — the controller is signing not only the reply but the working paper that supports it.
Section 50 interest recompute. For Option A or C, the interest is recomputed on the day of intended DRC-03 payment (not on the day the draft was prepared) so the day count is current. On the illustrative Rs 20,000 discharged 47 days after the original due date instead of 45, the interest recomputes to Rs 20,000 multiplied by eighteen per cent multiplied by 47 divided by 365 — approximately Rs 464 rather than Rs 444.
DRC-03 generation. The DRC-03 challan is generated on the portal against the DRC-01B intimation reference, payment discharged from the electronic cash ledger, and the acknowledgement reference number captured.
Part B submission. The Part B reply is filed on the portal, referencing the DRC-03 (if Option A or C) or attaching the reconciliation working paper (if Option B or C). The portal returns a separate acknowledgement reference number for the reply itself.
Archive. The DRC-01B PDF, the portal screenshots at intimation and at reply submission, the reconciliation working paper, the DRC-03 challan and acknowledgement, the Part B acknowledgement reference number, and the controller sign-off memo are filed in the triage folder. Cross-reference the folder to the reconciliation process design register — the failure mode is logged so the Day 17 GSTR-1 versus GSTR-3B reconciliation catches the class next month before the portal fires another intimation.
By the end of Hour 72, the DRC-01B is closed on the portal, the exposure profile is either closed (Option A) or defensibly recorded (Option B or C), and the triage folder is ready for a Section 73 or Section 74 assessment years later if the CBIC ever revisits.
The adjacent notice — DRC-01C on the input side
DRC-01B is the outward-side intimation. The DRC-01C intimation under Rule 88D is the inward-side counterpart — it fires when the ITC availed in GSTR-3B Table 4 exceeds the ITC available in GSTR-2B beyond the Rule 36(4) ceiling, and the reply window is thirty days rather than seven. The triage shares the four-block structure but the working paper set is different: purchase register versus GSTR-2B versus IMS action log, not GSTR-1 versus GSTR-3B. Both close with an update to the reconciliation process design register so the monthly close catches the class next cycle.
When the manual triage playbook outgrows itself
The 72-hour triage is designed for a finance team that receives a DRC-01B once a quarter or less. Above roughly two DRC-01Bs a quarter, on multi-GSTIN groups where each GSTIN can receive its own intimation, or in aggregator-heavy revenue models where the Table 6.2 TDS and TCS reconciliation surface alone produces a monthly DRC-01B pattern, the triage stops being a scheduled exercise and becomes a continuous background function.
At those thresholds, the value of a continuously refreshed reconciliation surface — where the GSTR-1 versus GSTR-3B match runs every day rather than every Day 17 — is that the intimation is caught by internal reconciliation twenty-four hours before the portal fires it, giving the tax team a full extra week of runway inside the seven-day clock. The reconciliation playbook pillar documents the operational cadence, and TransactIG reconciliation infrastructure is what the pattern moves to when the seven-day clock stops leaving room for a considered reply.
Where this fits
- TransactIG — reconciliation infrastructure
- GST reconciliation software India
- Reconciliation software India — pillar guide
- TDS reconciliation software India
Related reading
- The reconciliation playbook — monthly close pillar
- GSTR-1 vs GSTR-3B runbook — the Days 16 to 20 sibling window this triage patches after the fact
- GSTR-1 vs GSTR-3B reconciliation failure modes — the design layer
- DRC-01B reply guide — the reference for the seven-day reply mechanics
- DRC-01C ITC mismatch reply — the adjacent notice on the input side
- GSTR-9C three-way mismatch reconciliation — where an unresolved DRC-01B lands at year-end
- Invoice Management System reconciliation
- Section 16(4) ITC time bar
Content authored by practitioners with experience at Amazon India, Intuit QuickBooks, and the Tata Group. Meet the team →
- ▸ Rule 88C, Central Goods and Services Tax Rules 2017 (inserted by Notification 26/2022-Central Tax dated 26 December 2022) — Manner of dealing with difference in liability reported in statement of outward supplies and that reported in return. Where the tax payable by a registered person in accordance with the statement of outward supplies furnished by him in FORM GSTR-1 for a tax period exceeds the tax paid by such person in the return furnished for the same period in FORM GSTR-3B by such amount and by such percentage as may be recommended by the Council, the said registered person shall be intimated of such difference in Part A of FORM GST DRC-01B, electronically, on the common portal. The registered person shall, within a period of seven days of such intimation, either pay the amount of the differential liability with interest under Section 50 through FORM GST DRC-03 or furnish a reply in Part B of FORM GST DRC-01B explaining the reasons for the difference. The seven-day clock runs from the intimation date on the common portal, not from the date the finance team opened the intimation.
- ▸ Section 39(9), Central Goods and Services Tax Act 2017 — Rectification of returns. Any omission or incorrect particulars discovered in a return furnished under Section 39 shall be rectified in the return to be furnished for the month or quarter during which such omission or incorrect particulars are noticed, subject to payment of interest under this Act. No such rectification shall be allowed after the thirtieth day of November following the end of the financial year to which such details pertain, or the actual date of furnishing of the relevant annual return, whichever is earlier. Where a DRC-01B intimation for an FY 2025-26 tax period arrives after 30 November 2026, the amendment pathway has already closed and the reply cannot rely on a future GSTR-3B correction.
- ▸ Section 50, Central Goods and Services Tax Act 2017 — Interest on delayed payment of tax. Every person liable to pay tax in accordance with the provisions of this Act or the rules made thereunder who fails to pay the tax or any part thereof to the Government within the period prescribed shall for the period for which the tax or any part thereof remains unpaid, pay, on his own, interest at such rate not exceeding eighteen per cent per annum. Interest under Section 50 accrues from the date on which the tax became payable through the affected GSTR-3B and is computed on the differential amount for the days elapsed from the original due date to the DRC-03 payment date.
- ▸ Section 73, Central Goods and Services Tax Act 2017 — Determination of tax not paid or short paid or erroneously refunded or input tax credit wrongly availed or utilised for any reason other than fraud or any wilful misstatement or suppression of facts. Where a proper officer determines a shortfall on grounds other than fraud, the penalty is ten per cent of the tax involved or ten thousand rupees, whichever is higher. A DRC-01B differential paid voluntarily through DRC-03 within the seven-day reply window attracts no Section 73 penalty; a differential contested and later confirmed in adjudication attracts the ten per cent floor.
- ▸ Section 74, Central Goods and Services Tax Act 2017 — Determination of tax not paid or short paid or erroneously refunded or input tax credit wrongly availed or utilised by reason of fraud or any wilful misstatement or suppression of facts. The penalty escalates to one hundred per cent of the tax evaded or ten thousand rupees, whichever is higher. The classification between Section 73 and Section 74 turns on documentary evidence of intent — a DRC-01B reply that is contemporaneous, supported by working papers, and signed off at controller level is the primary evidentiary defence against a subsequent Section 74 characterisation.
- ▸ Section 122, Central Goods and Services Tax Act 2017 — Penalty for certain specified offences. Where a taxable person supplies any goods or services without issuance of an invoice, issues an incorrect or false invoice, collects any amount as tax but fails to pay it to the Government beyond three months from the date on which such payment becomes due, or fails to furnish returns under Section 39, the penalty is ten thousand rupees or an amount equivalent to the tax evaded or the tax not paid, whichever is higher. Section 122 sits alongside the Section 73 or Section 74 recovery machinery and can be invoked independently where a specified offence is made out on the DRC-01B facts.
- ▸ FORM GST DRC-03 — voluntary payment of tax — The voluntary payment form on the GST common portal through which a registered person can discharge a self-ascertained liability. A DRC-03 challan generated against the DRC-01B intimation reference number for the same GSTIN and tax period is the mechanism by which Option A of the reply — voluntary payment with interest under Section 50 — is discharged. The DRC-03 payment reference is what closes the DRC-01B on the portal.