Input tax credit management

Input tax credit in the current product is visible through posted purchase tax transactions, GSTR-2B data and the ITC tables computed on GSTR-3B. xMatix also contains lower-level services for a separate ITC-ledger lifecycle, Rule 42 calculation, supplier reconciliation and statutory time-limit checks, but those services do not currently have a runtime action, page or scheduled caller. This page separates the workflow you can use today from those unexposed capabilities.

The implemented path

1. A posted purchase supplies the books evidence

Posted bills and purchase documents create input TaxTransaction rows. Those rows carry the GST registration, document, tax head, value and eligibility information used by the supported processors. A Draft or unposted bill contributes no tax transaction and therefore cannot appear in the books side of GSTR-2B or the ledger-derived portions of GSTR-3B.

Review source eligibility carefully. A tax transaction classified as blocked or ineligible is evidence for reversal/disclosure; it must not be treated as available credit merely because a supplier reported the document.

2. GSTR-2B supplies the statement comparison

GSTR-2B processing materializes the supported books-side purchase sections. Portal-side statement data must be loaded through an explicit import or integration. The GSTR-2B reconciliation action then compares the two sides at document level.

GSTR-2B rows can hold imported IMS status. GSTR-3B excludes a row stored with IMS status R, but the current GSTR-2B handler does not expose a persisted Accept/Reject action, decision reason or reviewer audit. Treat the status as authoritative only when a controlled external source populated it.

3. GSTR-3B computes the supported credit rows

GSTR-3B Compute currently uses these sources:

Rule 42/43 proportional reversal remains a manual GSTR-3B row. Compute preserves manual rows while refreshing only rows marked as auto-filled.

The implemented Rule 37 tracker

Rule 37 tracking is wired into GSTR-3B Compute. For eligible input-tax rows linked to a Bill, the tracker derives a due date 180 days after the source document date and stores whether a reversal or reclaim has already been associated with a period.

• If the Bill remains unpaid after that due date, Compute can produce the temporary reversal in GSTR-3B.
• A Bill is treated as paid when its open amount is no longer positive; direct payment records linked by Bill ID also contribute to the settlement evidence used by the tracker.
• After payment, a later Compute can produce the reclaim.
• Stored reversed-in and reclaimed-in period markers prevent the same Bill from being reversed or reclaimed repeatedly.

This behavior depends on settlement being recorded against the Bill. A payment that is posted elsewhere but not applied to the Bill can leave its open amount outstanding and therefore cannot prove payment to the tracker.

Capabilities that are not currently exposed

The source contains service methods for period availment, Rule 42 reversal, net-ITC calculation and supplier-level ITC-to-GSTR-2B reconciliation. A GST time-limit service also contains statutory cut-off calculations. The current runtime has no handler action, UI caller or scheduled caller for those operations. Another unused GST-return service references the net-ITC method, but that service itself is not part of a live workflow.

Consequently, do not currently claim that xMatix:

• automatically posts every eligible credit into a separate ITCLedger lifecycle;
• automatically calculates or posts a Rule 42/43 reversal;
• enforces the statutory availment cut-off during a live save or return action; or
• exposes the service-level supplier reconciliation as an operational screen.

Those classes are implementation groundwork, not user-facing evidence. A generic entity form for GSTR-2B would not demonstrate these services, so this page intentionally has no screenshot until an exact ITC-management surface is wired into the product.

Recommended operating procedure

1. Post purchase documents only after checking GSTIN, document date, tax heads and eligibility classification.
2. Process the matching GSTR-2B books side and load the portal statement through your controlled import or integration.
3. Investigate reconciliation differences at document level; separately retain evidence for any imported IMS status.
4. Review bill settlement and open amounts before GSTR-3B Compute so Rule 37 has reliable payment evidence.
5. Compute GSTR-3B, then tie 4A, 4B and 4D to the exact GSTR-2B and tax-transaction sources named above.
6. Calculate Rule 42/43 outside the unexposed service, enter the approved manual return row and retain the workpaper.
7. Apply statutory time-limit review as a manual control until a runtime validation explicitly exposes the existing time-limit logic.

Common questions

Why did a Rule 37 reversal appear?

Trace the referenced Bill. Its due date has passed and xMatix still sees a positive open amount or no qualifying settlement evidence. Correct an incorrectly unapplied payment at the Bill; do not delete the return row to hide the source-state problem.

Why did a paid Bill not reclaim?

Confirm the payment is applied to that Bill and that its open amount is no longer positive. Then Compute an open GSTR-3B period and inspect the tracker's stored reversed/reclaimed period markers.

Where do I run ITC availment or Rule 42?

There is currently no supported runtime action for the service-level ITC availment or Rule 42 methods. Use the implemented GSTR-2B and GSTR-3B flow, and maintain the Rule 42 calculation and approval as a manual workpaper and manual GSTR-3B row.

Related topics

• GSTR-2B — inward supplies and ITC
• GSTR-3B — the summary return
• Recording and applying payments