TL;DR: A GST state code is a two-digit number assigned to each Indian state and union territory, forming the first two digits of a GSTIN and appearing on every GST invoice and e-way bill. Getting it wrong is a common, avoidable compliance error that delays shipments and can trigger the wrong tax treatment.
A wrong state code on an invoice sounds like a small typo. In practice it can mean the tax split gets calculated wrong, or an e-way bill gets rejected because the supplier’s and buyer’s state codes do not line up with the transaction.
What Is a GST State Code?
A GST state code is a two-digit numeric code assigned by the government to each Indian state and union territory, and it forms the first two digits of every GSTIN registered in that state.
The same code is required on every GST invoice, e-way bill, and GST return, since it determines whether a transaction is intra-state, where CGST plus SGST applies, or inter-state, where IGST applies.
State codes are standardized nationally and do not change, so once you know your own state’s code and your customer’s or vendor’s, the same numbers apply across every transaction.
Why Getting the State Code Right Matters for Manufacturers
Where GST State Codes Are Used
The same two-digit code shows up in four places on every transaction:
GSTIN. The first two digits of every business’s 15-digit GSTIN identify the state it is registered in.
Tax invoices. The place of supply is determined using the buyer’s state code, which decides whether CGST plus SGST or IGST applies.
E-way bills. Both the supplier’s and recipient’s state codes must be entered correctly, a mismatch is one of the most common reasons an e-way bill gets rejected or flagged.
GST returns. State-wise codes are used to report inter-state and intra-state supply separately in GSTR filings.
Common GST State Code Mistakes
The same errors show up repeatedly on manufacturer invoices and e-way bills:
Using an outdated or incorrect code. A typo in the two-digit code on an invoice can cause the wrong tax treatment to apply, even if the rest of the invoice is correct.
Mismatched supplier and recipient codes on an e-way bill. If the codes entered do not match the actual GSTINs, the e-way bill can get rejected or held up at a checkpoint.
Confusing a similar-sounding state’s code. States with similar names or adjacent numbers get mixed up when entered manually without a lookup reference.
Not updating billing software after a new registration. A business that registers a new GSTIN in a different state but does not update its billing system keeps issuing invoices under the wrong state code.
Assuming the buyer’s billing and shipping state are the same. For determining IGST vs CGST plus SGST, what matters is the place of supply, which is not always the same as the shipping address.
Are your invoices and e-way bills pulling the state code automatically from the GSTIN, or does someone type it in by hand every time?
TranZact’s GST e-invoicing pulls the state code directly from the registered GSTIN on both sides of the transaction, so it does not depend on someone typing the right two digits by hand every time.
Book a free demo →
Manual State Code Entry vs Automated GSTIN-Based Entry
Error risk: manual entry risks a typo in the two-digit code; automated entry pulls the code directly from the registered GSTIN.
Speed: manual entry takes an extra lookup step per invoice; automated entry is instant.
E-way bill rejections: manual entry is the more common source of a supplier or recipient code mismatch; automated entry keeps both sides consistent with the GSTIN on file.
Update handling: manual entry needs someone to remember a new registration or state change; automated entry updates the moment the GSTIN master record is updated.
Manufacturer relevance: the risk grows with transaction volume, a manufacturer issuing dozens of invoices a day has more chances for a manual entry error than one issuing a handful.
How TranZact Handles GST State Codes
TranZact’s GST e-invoicing and IRN generation pull the correct state code directly from each party’s registered GSTIN, so invoices and e-way bills stay consistent without a manual lookup step.
It does not replace your accountant’s judgment on place-of-supply edge cases. What it fixes is the routine part, getting the two-digit code right on every single invoice, automatically.
FAQs
What is a GST state code?
A two-digit numeric code assigned to each Indian state and union territory, forming the first two digits of every GSTIN registered in that state, and required on GST invoices, e-way bills, and returns.
Why do e-way bills get rejected due to state codes?
If the supplier’s or recipient’s state code entered doesn’t match their actual registered GSTIN, the e-way bill system flags or rejects it, since the code determines the transaction’s tax treatment and validity.
Does the GST state code ever change?
No, state codes are standardized nationally and do not change. What can change is which code applies to a specific business, if it registers a new GSTIN in a different state.
How is the GST state code different from a PIN code?
A PIN code identifies a specific postal area within a state. A GST state code is a two-digit number identifying the entire state or union territory, used specifically for GST registration and compliance, not postal delivery.
Where can I find my GST state code?
It is the first two digits of your GSTIN. If you know your GSTIN, you already have your state code, no separate lookup is needed.
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