What is Form GST DRC-01B?

Under rule 88C of the CGST Rules, it is the intimation sent when tax payable as per GSTR-1 (as amended in GSTR-1A) or IFF for a tax period exceeds tax payable as per GSTR-3B by an amount and percentage recommended by the GST Council. Part A shows the difference; the taxpayer pays through DRC-03 with section 50 interest or explains in Part B within seven days.

What is Form GST DRC-01C?

Under rule 88D, it is the intimation sent when ITC availed in GSTR-3B exceeds ITC available in GSTR-2B by an amount and percentage recommended by the GST Council. The taxpayer pays the excess with interest through DRC-03 or explains in Part B within seven days.

What happens if Part B is not filed?

Rule 59(6)(d) and (e): GSTR-1 or IFF for a subsequent tax period cannot be filed until the amount is paid or a reply is filed. Unpaid, unexplained or unaccepted amounts are recoverable under section 79 (DRC-01B) or can be demanded under section 73, 74 or 74A (DRC-01C).

What is the threshold for DRC-01B and DRC-01C?

The rules leave it to the GST Council and the GST portal FAQs call it a pre-defined limit and configurable percentage. We did not find the current figures in an official source, so check before quoting a number.

Is a DRC-03 payment compulsory to reply?

No. The GST portal manual says Part B can be filed with a DRC-03 ARN, a reason and explanation, or both, and entering an ARN is not mandatory.

DRC-01B and DRC-01C sheet for CA firms: catch GSTR-1 vs GSTR-3B and GSTR-2B vs GSTR-3B gaps for October 2026 before GSTR-1 is blocked

Updated 24 Oct 2026 · Disclosure: the white-label calendar linked below is an Unadhi product (₹999/year). This guide is for information only, not professional advice.

What you get: a ready-to-copy Google Sheet layout that catches GST return mismatches before they turn into a blocked GSTR-1. Tab 1 has one row per client per tax period and compares tax in GSTR-1 (as amended in GSTR-1A, or IFF) with tax in GSTR-3B. Tab 2 compares ITC available in GSTR-2B with ITC claimed in GSTR-3B. Tab 3 tracks every DRC-01B and DRC-01C intimation with a 7-day reply-by date, days left and a "GSTR-1 blocked?" flag. You also get a made-up example, a plan from GSTR-3B for October (20 November) to GSTR-1 for November (11 December) and a WhatsApp message for clients.

Short answer (checked 24 Oct 2026): if tax in GSTR-1/IFF is higher than tax in GSTR-3B beyond a limit set on the portal, the client gets Form GST DRC-01B (rule 88C). If ITC claimed in GSTR-3B is higher than ITC in GSTR-2B beyond a limit, the client gets Form GST DRC-01C (rule 88D). Either way the client must pay through DRC-03 with interest, or explain, in Part B within seven days. Until Part B is filed, GSTR-1/IFF for the next period cannot be filed (rule 59(6)(d) and (e)). The rules leave the amount and percentage to the GST Council, and the portal calls them "pre-defined" and "configurable"; we did not find the figures in an official source, so the sheet uses your own alert levels.

What the rules say

Output tax gap, rule 88C(1). Where tax payable as per GSTR-1, "as amended in FORM GSTR-1A if any", or IFF for a tax period exceeds tax payable as per GSTR-3B for that period "by such amount and such percentage, as may be recommended by the Council", the person is told of the difference in Part A of DRC-01B on the portal and by email, and directed to pay the difference with section 50 interest through DRC-03, or explain it, within seven days. Rule 88C was inserted by Notification 26/2022-CT; the GSTR-1A words came in through Notification 12/2024-CT.
Reply, rule 88C(2). Pay fully or partly through DRC-03 and give the details in Part B of DRC-01B, or give reasons in Part B for any part left unpaid.
If nothing happens, rule 88C(3). If the amount stays unpaid and there is no explanation, or the explanation is not accepted by the proper officer, it is recoverable under section 79.
ITC gap, rule 88D(1)-(2). Where ITC availed in GSTR-3B for a tax period or periods exceeds ITC available in GSTR-2B by such amount and percentage as the Council recommends, the person gets Part A of DRC-01C and must pay the excess with section 50 interest through DRC-03, or explain, in Part B within seven days. Inserted by Notification 38/2023-CT.
If nothing happens, rule 88D(3). The amount can be demanded under section 73 or 74, or section 74A (words inserted with effect from 1 November 2024 by Notification 20/2024-CT).
The block, rule 59(6)(d) and (e). A person who received a rule 88C or 88D intimation "shall not be allowed to furnish" GSTR-1 or IFF for a subsequent tax period unless they have paid the amount or filed a reply explaining what remains unpaid.
Portal FAQs. The intimation comes by email and SMS with a Reference Number, and is also under Services > Returns > Return Compliance > Liability Mismatch (DRC-01B) or ITC Mismatch (DRC-01C). For QRMP filers it is generated after the quarterly GSTR-3B; for monthly filers after each monthly GSTR-3B. After Part B is filed, GSTR-1/IFF can be filed straight away (log out and in again if it does not unlock).
Part B details from the portal manuals. Part B has two sub-parts: the ARN of a DRC-03 payment, and a reason with an explanation of up to 500 characters (four listed reasons plus "other"). You can use either or both; an ARN is not compulsory. The DRC-03 must be for the same GSTIN, filed on or after the date of Part A, for the same period (for quarterly filers, at least one month of the quarter), with cause of payment "Liability mismatch - GSTR-1 to GSTR-3B" (DRC-01B) or "ITC mismatch - GSTR-2A/2B to GSTR-3B" (DRC-01C). Filing is with EVC or DSC.
Who gets them. The FAQs list regular taxpayers (including SEZ units and developers) and casual taxpayers, plus taxpayers who opted in or out of composition (DRC-01B) or opted out of composition (DRC-01C).
The limits. Neither rule states a rupee amount or percentage. We did not find an official notification or portal page giving the current figures, so check before you quote any number to a client. Figures circulating online are not used here.

Tab "Liability": one row per client per tax period (DRC-01B check)

Put your own alert levels in a Settings tab and name the cells ALERT_AMT (for example ₹50,000) and ALERT_PCT (for example 0.05). These are your firm's early-warning levels, not the portal's.

Col	Header	What goes in
A	Client	Name
B	GSTIN	Typed
C	Tax period	Oct-2026, or Oct-Dec 2026 for QRMP
D	Tax in GSTR-1 / IFF, after GSTR-1A (₹)	IGST + CGST + SGST + cess on outward supplies, net of credit notes
E	Tax in GSTR-3B (₹)	Output tax declared in Table 3.1 (and 3.1.1 where relevant)
F	Gap (₹)	`=D2-E2` (a positive figure is the risk)
G	Gap %	`=IF(D2=0,0,F2/D2)`
H	Our alert	`=IF(AND(F2>0,OR(F2>=ALERT_AMT,G2>=ALERT_PCT)),"Explain or pay before filing","OK")`
I	Reason	Invoice in GSTR-1 but tax paid in an earlier or later 3B, typo in 3B, amendment in GSTR-1A, and so on
J	Action	Correct in next 3B / pay via DRC-03 / keep working papers ready

Tab "ITC": one row per client per tax period (DRC-01C check)

Col	Header	What goes in
A	Client	Name
B	GSTIN	Typed
C	Tax period	As in Tab 1
D	ITC available in GSTR-2B (₹)	From the 2B summary for the period
E	ITC claimed in GSTR-3B (₹)	Table 4 net ITC
F	Excess claimed (₹)	`=E2-D2` (a positive figure is the risk)
G	Excess %	`=IF(D2=0,IF(E2>0,1,0),F2/D2)`
H	Our alert	`=IF(AND(F2>0,OR(F2>=ALERT_AMT,G2>=ALERT_PCT)),"Explain or reverse before filing","OK")`
I	Reason	Import of goods (IGST paid at customs), reverse charge, ISD credit, credit of an earlier period now in 2B, and so on
J	Working papers	Link to bill of entry, RCM challan, ISD invoice, supplier invoice

Tab "Intimations": one row per DRC-01B or DRC-01C received

Col	Header	What goes in
A	Client	Name
B	Form	"DRC-01B" / "DRC-01C"
C	Reference Number	From the email or SMS
D	Tax period	As in Part A
E	Amount in Part A (₹)	From Part A
F	Date of Part A	Date
G	Reply by	`=F2+7` (seven days under rules 88C(1)/88D(1); check how your officer counts the days)
H	Days left	`=IF(K2="Filed","",G2-TODAY())`
I	DRC-03 ARN (if paid)	Cause: "Liability mismatch - GSTR-1 to GSTR-3B" or "ITC mismatch - GSTR-2A/2B to GSTR-3B"
J	Amount explained, not paid (₹)	With the reason (max 500 characters on the portal)
K	Part B status	"Pending" / "Filed"
L	GSTR-1 blocked?	`=IF(K2="Filed","No","Yes: next GSTR-1/IFF cannot be filed")`
M	Check	`=IF(K2<>"Filed",IF(H2<0,"Late: file Part B now","Due in "&H2&" days"),"OK")`

Made-up example (not a real client)

Example only: "Sharada Traders" (made-up name), a monthly filer. October 2026 GSTR-1 shows tax of ₹4,20,000. Its GSTR-3B for October shows ₹3,60,000, because two invoices worth ₹60,000 of tax were shown in GSTR-1 but missed in 3B. Tab 1: gap ₹60,000, gap 14.3%, so "Explain or pay before filing" with your example alert levels of ₹50,000 / 5%. Tab 2: GSTR-2B ITC ₹2,10,000, 3B ITC ₹2,40,000 because ₹30,000 of IGST on an import of goods is not in 2B; excess ₹30,000, 14.3%, so "Explain or reverse before filing", with the bill of entry linked as working paper.

Step	What the firm does (example)
Before 3B	Adds the missed invoices to the October 3B instead of paying later, so the Tab 1 gap falls to ₹0.
If a DRC-01C arrives	Files Part B with the reason "import of goods" and the bill of entry detail; no DRC-03 needed for that part.
Same day	Marks Part B "Filed" in Tab 3, so "GSTR-1 blocked?" shows "No".

(Example names and figures only. Whether a reason is accepted is for the proper officer.)

Plan to 11 December

Date	Do this
By 31 Oct	Copy the three tabs. Set ALERT_AMT and ALERT_PCT. Fill Tab 3 with any open DRC-01B/01C from earlier periods.
11 to 18 Nov	After GSTR-1 for October and GSTR-2B are ready, fill Tabs 1 and 2 for every monthly client. Fix gaps in the October 3B itself where you can.
By 20 Nov	File GSTR-3B for October (monthly filers).
21 Nov onwards	Check Return Compliance on the portal and client email/SMS daily. Log every intimation in Tab 3 the same day.
Within 7 days of each Part A	Pay through DRC-03 with section 50 interest or explain in Part B. Collect working papers first.
Before 11 Dec	Make sure no row in Tab 3 says "Yes" under GSTR-1 blocked, so GSTR-1 for November can be filed on time.
QRMP clients	Repeat after the Oct-Dec quarterly 3B (see the quarterly 3B due dates).

WhatsApp message to a client

"Hello [name], the GST portal can send an automatic notice (DRC-01B or DRC-01C) when GSTR-1 and GSTR-3B, or GSTR-2B and GSTR-3B, do not match. A reply is needed within 7 days, and until it is filed your next GSTR-1 is blocked. If you get an email or SMS from GST with a Reference Number, please forward it to us the same day. Please also send any import bills of entry and reverse-charge challans for October by 15 November. Thank you."

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Sources

This sheet is a working aid, not professional advice. Portal limits and due dates can change; check the portal before you rely on them. Checked on 24 October 2026. Spot an error? Write to mininglife7@gmail.com.

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Unadhi Guides are free, independent explainers. We correct errors as soon as we find them: write to mininglife7@gmail.com.