Multi-State Seller Compliance Toolkit
Free tools and a step-by-step checklist for e-commerce sellers managing GST across multiple states — GSTIN decoder, state code finder, and APOB registration.
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If you sell through Amazon FBA, Flipkart Fulfilment, or a quick-commerce platform like Blinkit or Zepto, your inventory almost certainly sits in more than one state — and under GST law, that changes your registration obligations in ways a single-warehouse D2C seller never has to think about. This page bundles the tools and the checklist you need to get multi-state GST compliance right, in one place.
The Two Free Tools
GSTIN Verification & Decoder — paste any 15-character GSTIN to instantly decode its state code, embedded PAN, entity number, and check digit. Use this to sanity-check a supplier's or buyer's GSTIN before you invoice them, or to confirm your own registration details match what you expect.
GST State Code Finder — look up the 2-digit GST state code for any Indian state or union territory. Useful when you're registering a new APOB and need to confirm the exact code that should appear in the resulting GSTIN.
The APOB Registration Checklist
Every warehouse, fulfilment center, or dark store you supply into — beyond your principal place of business — needs to be added as an Additional Place of Business (APOB) under your GSTIN in that state. Work through this before you start shipping inventory into a new location:
- Confirm whether the new location needs an APOB or a fresh GSTIN. If you already hold a GSTIN in that state, a new warehouse there is an APOB addition to your existing registration. If it's a state you're not yet registered in, you need a new, separate GSTIN — APOB doesn't substitute for that.
- Gather the location's address proof — a rent agreement, NOC from the property owner, or utility bill in the business's name, the same document types required for your principal place of business.
- File the amendment on the GST portal — Services → Registration → Amendment of Registration (Non-Core Fields for most APOB additions), adding the new address under "Additional Places of Business."
- Wait for approval before invoicing from that location. Using an unregistered APOB to raise invoices creates a mismatch that can block your buyer's ITC and complicate your own GSTR-1 reconciliation.
- Repeat per state, per location — if you're supplying dark stores in three states for a quick-commerce platform, that's three separate amendment filings (or new GSTINs, per point 1), not one blanket update.
If you're onboarding a quick-commerce channel specifically, see our quick-commerce GST and dark-store registration guide for the platform-specific detail (Blinkit, Zepto, Swiggy Instamart all follow this same APOB requirement). If you're a small seller weighing whether a newer, simplified registration route applies to you before going through the full amendment process, check our simplified GST registration guide for e-commerce sellers.