Customer Master Data for GST: GSTIN, Legal Name and Place of Supply in Your CRM
Capture each customer's GSTIN, legal name as registered, billing and shipping states and registration status, and verify them on the GST portal before the first invoice. The state decides whether you charge IGST or CGST plus SGST. If you charged the wrong type, you must pay the correct tax and claim the wrong one back within two years.
Sales teams create customer records in a hurry: a trade name from a visiting card, the head office address, a GSTIN copied from an old email. The billing system then uses that record to decide the tax type on every invoice. If the state is wrong, every invoice is wrong, and the fix is slow. This post covers what to capture, how to validate it and what happens when it goes wrong.
What the customer master must hold
| Field | Why it matters |
|---|---|
| GSTIN | Needed for a B2B invoice and for the customer's input credit |
| Legal name as registered | Must match the GST record; trade names alone cause disputes |
| Billing address and state | Location of the recipient for services |
| Shipping address and state, per delivery | Place of supply for goods moved to that place |
| Registration type | Regular, composition, SEZ unit or developer, unregistered |
| Status and date checked | Active, suspended or cancelled, as of when |
| Contact for GST matters | Who to call when an invoice is rejected |
A GSTIN has 15 characters: the first two are the state code, the next ten are the customer's PAN, followed by an entity number, a default letter and a check digit. If the first two digits do not match the billing state, stop and ask.
How the state drives the tax type
The billing system compares the place of supply with your own state:
- ✓Same state: CGST plus SGST.
- ✓Different state: IGST.
For goods, the place of supply is generally where the movement ends, so the ship-to state matters, and a bill-to-ship-to sale follows the bill-to party's location. For most services to a registered customer, it is the customer's registered location. A customer with GSTINs in several states needs a separate record, or at least a separate GST profile, for each one. Invoicing the Karnataka branch under the Maharashtra GSTIN is one of the commonest errors.
Rule 46 of the CGST Rules also requires the invoice to show the recipient's name, address and GSTIN, and for inter-state supplies, the place of supply with the state name. Those fields come straight from the master.
Validating on the GST portal
- Go to the Search Taxpayer option on gst.gov.in and enter the GSTIN. No login is needed.
- Compare the legal name, trade name, principal place of business and constitution with what the customer gave you.
- Check the status. A cancelled GSTIN shows the date of cancellation; a suspended one means cancellation proceedings are pending.
- Check the return-filing table. A customer who has stopped filing may soon be cancelled.
- Record the date you checked. Re-check every active customer at least quarterly, and before any large order.
E-invoicing systems also reject invoices with invalid GSTINs, but they will not catch a valid GSTIN from the wrong state or the wrong branch.
Handling a cancelled or suspended GSTIN
- ✓Cancelled before the invoice date: treat the customer as unregistered from the cancellation date. Bill as B2C, with the place of supply based on the address, and tell the customer it cannot claim credit.
- ✓Suspended: the customer cannot use credit while suspended. Ask about the status before billing large amounts, and get payment terms right.
- ✓Cancelled later with a back date: keep your proof that the GSTIN was active when you invoiced: the portal screenshot or search log with its date.
When the wrong tax type was charged
Paying IGST instead of CGST plus SGST (or the reverse) does not cancel out, even though the total is the same. The tax sits in the wrong account, and the customer often cannot use the credit.
| Route | How it works | Watch out |
|---|---|---|
| Credit note and fresh invoice | Issue a credit note under Section 34 for the wrong invoice and raise a fresh invoice with the right tax | Since 2025 your liability goes down only after the customer accepts or reverses credit on IMS. If you use this route, the refund route below is not available for the same transaction |
| Pay the right tax, then claim a refund | Pay the correct tax, then file Form GST RFD-01 for the wrong tax under Section 77 of the CGST Act or Section 19 of the IGST Act | File within two years from the date you paid the correct tax (Rule 89(1A)). No interest is payable on the correct tax |
CBIC Circular 162/18/2021-GST confirms the refund route is open whether you find the error yourself or a tax officer does.
A worked example
A Pune IT services firm bills a client registered in Bengaluru for a ₹5,00,000 project. The CRM record was created with the client's Mumbai office address, so the billing system charged Maharashtra tax.
| Charged | Correct | |
|---|---|---|
| Taxable value | ₹5,00,000 | ₹5,00,000 |
| CGST 9% | ₹45,000 | nil |
| SGST 9% | ₹45,000 | nil |
| IGST 18% | nil | ₹90,000 |
| Invoice total | ₹5,90,000 | ₹5,90,000 |
The client's Karnataka GSTIN cannot use Maharashtra CGST and SGST, so it refuses to pay the tax portion.
Fix through the refund route:
- The firm reports the invoice with IGST of ₹90,000 and pays it on 20 October 2026.
- It files RFD-01 for the ₹90,000 of CGST and SGST paid earlier. The deadline is two years from 20 October 2026, so before 20 October 2028.
- No interest is payable on the ₹90,000 IGST, because of Section 19(2) of the IGST Act.
- Until the refund arrives, ₹90,000 of the firm's cash is locked up.
The CRM record is corrected to the Bengaluru GSTIN, and the firm adds a rule: no invoice until the GSTIN state code matches the billing state.
Frequently asked questions
Can the sales team enter a GSTIN without checking it?
They can, but the record should stay "unverified" until accounts checks it on the portal. Block invoicing for unverified records.
The customer changed its address. What changes?
Update the master from the customer's amended GST registration, not from an email. If the state changed, the tax type may change too.
Is a trade name enough on the invoice?
Use the legal name as registered. The trade name can appear alongside it.
Does the two-year limit apply strictly?
Rule 89(1A) sets it, though some High Courts have allowed late claims on facts. Plan to file well within two years.
Sources
- ✓CBIC Circular 162/18/2021-GST on refunds under Section 77 CGST and Section 19 IGST
- ✓Search Taxpayer manual, GST portal
- ✓Understanding Section 77 CGST and Section 19 IGST, Taxmann
This is a summary, not legal advice. Confirm the place of supply for your transactions and refund timelines with your GST practitioner or on cbic-gst.gov.in.
Written by
Founder, Airwix Technologies (Sleet)
Vatsal Sutariya is the founder of Airwix Technologies in Ahmedabad, the company that builds Sleet: SleetHR for HR and payroll, and Sleet Accounting for GST billing and books. He writes about GST, invoicing, business tax and choosing software for Indian businesses, and checks each rule against the official notification before it is published.
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