What is the main difference between legacy GSTR-2B and the IMS regime?

Legacy GSTR-2B was a static, unchangeable pull of supplier data generated on the 14th. Under IMS, GSTR-2B is dynamic — recipient taxpayers actively curate credit by marking entries Accept, Reject, or Pending before GSTR-3B.

How has monthly reconciliation changed from a 2-way match to a 3-way match?

Previously, accountants matched Tally Books vs static GSTR-2B. Under IMS, accountants perform a 3-way match: Tally Books vs IMS Inward Feed vs Final GSTR-2B.

Can I still manually edit ITC figures in GSTR-3B Table 4 without IMS acceptance?

No. GSTR-3B Table 4 is hard-locked to GSTR-2B. Claiming ITC in excess of GSTR-2B without valid IMS acceptance triggers automated audit notices (DRC-01C).

How does AI purchase automation fit into the new IMS workflow?

AI invoice automation parses vendor PDFs, auto-extracts line items, and posts verified F9 Purchase Vouchers into Tally Prime. This eliminates manual entry typos that cause artificial IMS mismatches.

Current GST Practices vs IMS Portal Process Comparison (2026)

Quick Summary: What Is the Difference Between Pre-IMS Practices & 2026 IMS?

Pre-IMS compliance relied on static, post-facto GSTR-2B reconciliation after the 14th of the month. The 2026 IMS regime requires active, real-time 3-way matching (Tally Purchase Books vs IMS Queue vs GSTR-2B), where recipients explicitly Accept, Reject, or Pending supplier bills before GSTR-3B auto-populates.

Control Shift: From passive receipt of supplier errors to active gating via Accept/Reject.
Dynamic GSTR-2B: GSTR-2B is now curated by recipient actions rather than static portal pulls.
3-Way Match: Integrates internal AP voucher registers directly with the IMS queue.
Hard-Locked Returns: GSTR-3B Table 4 is hard-locked; no manual excess ITC overrides allowed.

1. Comprehensive Feature Comparison: Pre-IMS vs 2026 IMS Regime

The GST compliance ecosystem underwent a total operational shift in 2026. The table below details how legacy accounting practices compare with the current mandatory IMS workflow:

Compliance Parameter	Legacy Practice (Pre-IMS)	Current 2026 IMS Regime
GSTR-2B Nature	Static, unchangeable snapshot (14th)	Dynamic & Curated by Recipient Actions
Reconciliation Model	2-Way Match (Books vs GSTR-2B)	3-Way Match (Books vs IMS vs GSTR-2B)
Handling Supplier Errors	Discovered months later during audit	Rejected in real-time; forces GSTR-1A edit
In-Transit Goods (Sec 16(2)(b))	Manual Excel tracking & manual reversals	Marked 'Pending' cleanly in IMS
GSTR-3B Table 4 Locking	Manual entry overrides permitted	Hard-Locked to finalized GSTR-2B
Unactioned Bills (Cutoff)	N/A	Deemed Accepted automatically

Adapt to 3-Way Matching with TrulyInvoice AI

Ensure Tally purchase books match IMS vendor feeds with 99.8% accuracy.

In the 2026 IMS era, manual entry errors in Tally Prime (wrong bill numbers or invoice dates) break your 3-way match, forcing staff to resolve artificial portal discrepancies.

TrulyInvoice AI Solution: Upload supplier PDF bills or WhatsApp scans. AI auto-extracts HSN codes, invoice numbers, and GST totals, posting verified F9 Purchase Vouchers directly to Tally Prime in 15 seconds via Port 9000 local sync.

2. Impact on Daily Accounts Payable (AP) Workflows

The shift from static GSTR-2B to dynamic IMS changes how finance teams schedule their monthly routines:

Continuous Entry: Purchase invoices must be recorded as soon as physical bills arrive, avoiding month-end entry pileups.
Pre-14th Review: AP teams review supplier uploads between the 1st and 13th of every month.
Post-14th Action Re-computation: Any action modifications made between the 14th and 20th trigger a GSTR-2B re-computation before GSTR-3B submission.