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GST Reconciliation · ITC Verification

GST Reconciliation Software for High-Volume Indian Businesses

Rule 36(4) ended provisional ITC in 2022. Today, every rupee of Input Tax Credit you claim in GSTR-3B must be supported by an entry in your GSTR-2B — auto-populated on the GST portal from your suppliers' GSTR-1 filings. Unreconciled ITC is not a timing difference — it is a tax liability, recoverable with interest at 18% per annum. Manual reconciliation using spreadsheets fails at enterprise scale because it matches on a single field, produces an undifferentiated exception list, and leaves blocked credits, period mismatches, and supplier defaults unclassified. TransactIG automates GSTR-2B reconciliation at invoice level, classifies every mismatch by type, and gives your finance team a structured resolution queue before each GSTR-3B filing deadline.

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Rule 36(4)
ITC restricted to GSTR-2B
6 mismatch types
Detected and classified
2–4 weeks
Implementation
GSTR-1 + 2B + 3B
GST return coverage

Why GST ITC Reconciliation Is Now Mandatory

When GST was introduced in 2017, businesses could claim provisional ITC on invoices not yet reflected in the government's system — up to 20% initially, later reduced to 10%, and then to 5% of GSTR-2B-eligible credit. This buffer was eliminated with effect from 1 January 2022. Since then, Rule 36(4) permits ITC claims only on invoices that appear in GSTR-2B. There is no provisional credit, no grace period, and no self-assessment latitude on the ITC amount beyond what the portal reflects.

GSTR-2B is generated monthly between the 12th and 14th of each month, capturing all supplier GSTR-1 filings up to the 11th. Any supplier who files their GSTR-1 after the 11th will not appear in the current month's GSTR-2B — they will appear in the following month's statement. For enterprises with large supplier bases, this creates a systematic lag: invoices received and recorded in the purchase register in month N will not generate ITC until month N+1 if the supplier is a late filer. Identifying and quantifying this lag before filing GSTR-3B is only possible through a structured reconciliation of the purchase register against GSTR-2B.

The consequences of not reconciling are cumulative. Each month's unresolved ITC mismatch carries forward to GSTR-3B as either an overclaim (ITC claimed without GSTR-2B support — triggers demand) or an underclaim (ITC available in GSTR-2B but not captured — forfeits working capital). By the time the GSTR-9 annual return is due, the cumulative difference between Table 8A (ITC as per GSTR-2A/2B) and Table 8C (ITC claimed in GSTR-3B) must be reconciled and, where unexplained, attracts scrutiny from the GST department. Businesses that have maintained a disciplined monthly reconciliation produce this reconciliation in hours; those that have not face a year-end reconstruction exercise spanning 12 months of purchase data.

Beyond ITC verification, GST reconciliation also surfaces supplier compliance risk. A supplier who consistently fails to file GSTR-1 on time is creating a recurring ITC shortfall for every business they supply. Identifying these suppliers through reconciliation data allows procurement and finance teams to take commercial action — amending payment terms, requiring advance filing confirmation, or switching suppliers — rather than absorbing the ITC loss silently.

For a detailed walkthrough of the GSTR-2B download process and ITC matching methodology, see the GSTR-2B reconciliation guide. For the broader context of reconciliation infrastructure across Indian enterprise finance, see reconciliation software India.

What TransactIG GST Reconciliation Does

Six functional modules covering the full scope of GST ITC verification — from supplier filing status to annual GSTR-9 reconciliation.

01

GSTR-2B vs purchase register matching at invoice level

TransactIG ingests your GSTR-2B statement from the GST portal and your purchase register export from the ERP. It matches at invoice level — not at period aggregate — using GSTIN, invoice number, invoice date, and tax value as matching signals. Entries that do not match exactly are escalated through the four-pass engine before being classified as exceptions.

02

Supplier GSTIN validation and GSTR-1 filing status check

Before matching begins, TransactIG validates each supplier GSTIN in the purchase register against the GST portal to confirm the GSTIN is active and the supplier has filed their GSTR-1 for the relevant period. Invoices from non-filers are immediately flagged as SUPPLIER_NOT_FILED rather than passed to the match engine, which prevents false positives.

03

Section 17(5) blocked credit identification and exclusion

A configurable blocked credit ruleset covers all categories specified under Section 17(5) — motor vehicles, personal consumption goods, food and beverages, outdoor catering, club and health centre memberships, and works contract services for immovable property. Invoices matching these categories are excluded from ITC claims automatically and routed to the BLOCKED_CREDIT queue for documentation.

04

TCS (Section 52) and GST TDS (Section 51) classification

Marketplace sellers receive TCS deductions at 1% from e-commerce operators under Section 52. Government entity vendors face GST TDS at 2% on payments exceeding ₹2.5 lakh under Section 51. TransactIG processes settlement sidecar files from marketplace operators and purchase order data from government clients to match TCS and TDS credits appearing in the GST cash ledger against expected amounts.

05

ITC carry-forward tracking across periods

When a PERIOD_MISMATCH means ITC must be claimed in a different month than the invoice date, TransactIG tracks the carry-forward balance across periods. This ensures ITC is not double-claimed, not abandoned, and is claimed in the earliest eligible period — which is relevant for working capital planning and for the GSTR-9 annual reconciliation.

06

GSTR-9 annual reconciliation support

The GSTR-9 annual return requires reconciling cumulative ITC claimed in monthly GSTR-3B filings against the ITC available in GSTR-2A/2B across the full year. Differences must be declared in Table 8. TransactIG generates the GSTR-9 reconciliation summary from the monthly match data, eliminating the need to reconstruct the full year's reconciliation from spreadsheets at year-end.

GST Mismatch Types: Classification and ITC Impact

TransactIG assigns a structured mismatch code to every unmatched entry. Each code has a defined ITC impact and a specific resolution path — preventing unmatched entries from being treated as a homogeneous pending list.

Mismatch Type Cause ITC Impact Resolution
SUPPLIER_NOT_FILED Supplier hasn't filed GSTR-1 No ITC claimable Follow up; reverse if unresolved by September
AMOUNT_MISMATCH Invoice amount differs between your records and GSTR-2B Partial ITC only Raise credit/debit note or debit supplier
GSTIN_MISMATCH Supplier used wrong GSTIN in their return ITC wrongly credited Supplier correction return required
PERIOD_MISMATCH Invoice in different GSTR-2B month than expected ITC in wrong period Claim in correct period; track carry-forward
BLOCKED_CREDIT Invoice is for blocked supply under Section 17(5) No ITC claimable Classify and exclude; do not reverse if already excluded
CANCELLED_INVOICE Supplier cancelled invoice post-GSTR-2B auto-population ITC must be reversed Reverse in next filing; add interest at 18%

TransactIG assigns structured variance codes to each GST exception automatically. See variance taxonomy for the full classification schema.

How TransactIG GST Reconciliation Works

Three steps from GSTR-2B download to a structured exception queue — completed before the 20th of each month.

01

Download GSTR-2B

TransactIG ingests GSTR-2B data either through automated portal extract or manual JSON/Excel upload from the GST portal. Multi-GSTIN entities upload once per registered entity. The GSTR-2B data is parsed, structured, and indexed by supplier GSTIN, invoice number, and tax period — ready for matching.

02

Match against purchase register from ERP

The purchase register is exported from SAP, Oracle NetSuite, Tally Prime, Zoho Books, Busy Accounting, or Microsoft Dynamics using a pre-configured connector. TransactIG's four-pass engine matches GSTR-2B entries to purchase register entries using GSTIN, invoice number, date, and tax value — with configurable tolerance on amounts for rounding differences. Blocked credit invoices are identified and excluded before the match.

03

Exception queue with mismatch classification

Every unmatched entry receives a structured mismatch code: SUPPLIER_NOT_FILED, AMOUNT_MISMATCH, GSTIN_MISMATCH, PERIOD_MISMATCH, BLOCKED_CREDIT, or CANCELLED_INVOICE. The exception queue shows ITC impact per entry, recommended resolution action, and responsible party. Finance teams work from this queue rather than a raw unmatched list. Every resolution action is logged with timestamp and user identity for audit.

GST Reconciliation by Industry

The complexity of GST ITC reconciliation varies by industry. Different sectors face different mismatch patterns, apportionment requirements, and TCS/TDS obligations.

Retail and E-commerce

Marketplace sellers operating on Amazon, Flipkart, or Meesho receive TCS deductions at 1% of net value under Section 52 on each settlement. Reconciling TCS credits in the GST cash ledger against settlement statements from multiple platforms, while simultaneously matching supplier invoices in GSTR-2B for inbound goods, creates a two-track reconciliation requirement that manual processes routinely conflate. TransactIG handles both tracks separately. See the full coverage for retail and e-commerce reconciliation .

IT Services — Export Invoices and LUT

IT services companies exporting services under a Letter of Undertaking (LUT) raise zero-rated invoices. While no GST is charged on export invoices, ITC on input services used to provide those exports is claimable as a refund under Rule 89. TransactIG reconciles input credit on domestic purchases against export turnover, and ensures that ITC attributable to both taxable and exempt supplies is apportioned correctly under Rule 42/43 before the refund application is prepared.

Manufacturing — Input Credit on Capital Goods

Capital goods GST credit is available across two years under Section 16 — 50% in the year of acquisition and 50% in the following year. TransactIG tracks capital goods ITC separately from revenue ITC, schedules the second-year credit claim, and ensures the asset register entry and GSTR-2B entry for capital invoices are matched and documented for the GSTR-9C audit reconciliation.

Healthcare — Exempt Supplies and Partial ITC

Hospitals and diagnostic centres provide both exempt services (patient care) and taxable services (pharmacy, diagnostics for non-patients). Under Rule 42, ITC on common inputs must be apportioned between taxable and exempt activities. TransactIG applies the apportionment formula at the cost-centre level, identifies blocked credits on healthcare-specific expenditure, and prepares the Rule 42 working for inclusion in the monthly GSTR-3B and annual GSTR-9.

For marketplace sellers and aggregator platforms, see how platform settlement reconciliation handles the intersection of GST TCS, payout timing, and commission deductions in a single workflow.

Manual GST Reconciliation vs TransactIG

The difference is not speed — it is the structure of the output and the reliability of the ITC position before each GSTR-3B filing.

Dimension Manual / Spreadsheet TransactIG
Matching approach VLOOKUP on invoice number or GSTIN; single-field match only Four-pass engine using GSTIN, invoice number, date, and tax value; 51% to 88% match rate improvement
Mismatch classification Unmatched entries listed in a single "pending" tab with no classification Six structured mismatch types (SUPPLIER_NOT_FILED, AMOUNT_MISMATCH, GSTIN_MISMATCH, PERIOD_MISMATCH, BLOCKED_CREDIT, CANCELLED_INVOICE)
Blocked credit handling Manual line-by-line review against Section 17(5) list; prone to omission Configurable blocked credit ruleset applied before matching; automatic exclusion from ITC claims
ITC carry-forward tracking Tracked in a separate spreadsheet; reconciliation between months is manual Carry-forward balance tracked within the system across periods; included in GSTR-9 summary
Audit trail Version history in spreadsheet only; no record of who approved each adjustment Every match, override, and write-off logged with timestamp and user identity; exportable for GST audit

TransactIG is certified ISO 27001:2022. All reconciliation data is processed and stored in a cloud-only environment. For the full capability overview and ERP integration list, see the product page.

Frequently Asked Questions

What is GST reconciliation software?
GST reconciliation software is a tool that automatically matches the invoices appearing in your GSTR-2B (auto-populated from your suppliers' GSTR-1 filings on the GST portal) against the corresponding entries in your purchase register or ERP. The purpose is to verify that every Input Tax Credit (ITC) you intend to claim has a corresponding entry in GSTR-2B before you file your GSTR-3B return. Since Rule 36(4) came into effect in 2022, provisional ITC — the 5% buffer that previously allowed claims beyond GSTR-2B — has been eliminated entirely. Every rupee of ITC you claim must now be supported by a GSTR-2B entry. GST reconciliation software enforces this requirement at invoice level, identifies the type of mismatch for each unmatched entry, and gives your finance team a structured exception queue to resolve before the 20th of each month.
What is GSTR-2B reconciliation?
GSTR-2B is a read-only, auto-generated statement on the GST portal that is populated each month from your suppliers' GSTR-1 and GSTR-1A filings. It shows, for each of your GSTINs, which supplier invoices are available for ITC in that period. GSTR-2B reconciliation is the process of comparing this portal-generated statement against your own purchase register — verifying that each invoice you have recorded in your books also appears in GSTR-2B at the correct GSTIN, amount, and tax period. Under Rule 36(4), ITC can only be claimed on invoices reflected in GSTR-2B. If a supplier has not filed their GSTR-1, or filed it with errors, the invoice will not appear in your GSTR-2B and the corresponding ITC cannot be claimed — even if the physical invoice is in your possession and the payment has been made.
What happens if ITC is claimed without GSTR-2B support?
Claiming ITC not reflected in GSTR-2B is treated as an erroneous or excess ITC claim under the GST Act. When the GST department's system reconciles your GSTR-3B (where ITC is claimed) against the GSTR-2B available for your GSTIN, the unmatched portion will trigger a demand notice under Section 73 or Section 74. You will be required to reverse the ITC, pay the tax liability equivalent, and pay interest at 18% per annum on the amount from the date of the original filing. Where the department determines the claim was wilful, the interest rate increases to 24% per annum and penalty provisions apply. Unreconciled ITC also surfaces during the GSTR-9 annual return, where the cumulative difference between ITC claimed in GSTR-3B and ITC reflected in GSTR-2A/2B across the year must be declared and defended.
Which GST mismatches does TransactIG detect?
TransactIG classifies every unmatched entry in GSTR-2B reconciliation into one of six structured mismatch types. SUPPLIER_NOT_FILED: the supplier has not filed their GSTR-1 for the period, so the invoice does not appear in your GSTR-2B at all — no ITC is claimable until they file. AMOUNT_MISMATCH: the invoice amount or tax value in your purchase register differs from what the supplier reported in their GSTR-1 — only the amount in GSTR-2B is eligible for ITC. GSTIN_MISMATCH: the supplier quoted an incorrect GSTIN in their return, causing the ITC credit to appear against the wrong entity. PERIOD_MISMATCH: the invoice appears in a different month's GSTR-2B than expected, which means ITC must be claimed in that specific period and tracked across carry-forwards. BLOCKED_CREDIT: the invoice falls under Section 17(5) of the GST Act — vehicles, personal-use goods, food, club memberships, and other specified categories — and no ITC is available regardless of GSTR-2B appearance. CANCELLED_INVOICE: the supplier cancelled the invoice after GSTR-2B was auto-populated, requiring mandatory ITC reversal with interest.
How does TransactIG handle TCS from e-commerce operators?
Under Section 52 of the GST Act, e-commerce operators are required to collect Tax Collected at Source (TCS) at 1% of the net value of taxable supplies made through their platform. This amount is deducted from the settlement payout to the seller and deposited directly with the GST department, appearing as a credit in the seller's GST electronic cash ledger rather than as ITC in their electronic credit ledger. TransactIG handles TCS reconciliation by ingesting the settlement sidecar files provided by each marketplace — which itemise TCS deducted per settlement period — and matching them against the corresponding TCS credits reflected in the GST portal. For sellers operating across multiple platforms such as Amazon, Flipkart, or Meesho, each platform has a separate TCS credit line. TransactIG aggregates these, matches them to the cash ledger credit, and flags any difference between the TCS deducted per the settlement statement and the TCS credited by the GST portal.
How long does GST reconciliation software implementation take?
TransactIG GST reconciliation goes live in 2 to 4 weeks with no code development required. The implementation process has three stages. In week one, your ERP connection is configured — TransactIG supports SAP, Oracle NetSuite, Tally Prime, Zoho Books, Busy Accounting, and Microsoft Dynamics — and purchase register fields are mapped to the reconciliation schema (GSTIN, invoice number, date, taxable value, CGST, SGST, IGST). In week two, GSTIN configuration is completed for all entities in your GST registration, and the GSTR-2B download schedule is established (either manual upload or automated portal extract). In weeks three and four, a parallel run is conducted on the prior month's data to validate match rates and tune tolerance rules. After sign-off, the system is live for the current month's reconciliation cycle.
ISO 27001:2022 Certified · Cloud-only · No code development

Reconcile GSTR-2B before every GSTR-3B filing

TransactIG matches your purchase register against GSTR-2B at invoice level, classifies every mismatch, and gives your team a resolution queue — not a raw exception list.

Implementation in 2–4 weeks. Integrates with SAP, Oracle NetSuite, Tally Prime, Zoho Books, Busy Accounting, and Microsoft Dynamics.

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