Purchase

Set Supplier State, GST Type and GSTIN

For India GST, supplier identity affects purchase tax classification. Registered suppliers require a valid 15-character GSTIN; a recognized GSTIN state code can set the supplier state, and purchase processing uses that code before falling back to the typed state.

Menu path
Purchase -> Supplier List -> New or Edit -> Country, State and GST Fields
Verified from
Posnic demo and current POS source reviewed on 2026-09-08
Technical source evidence

frontend/modals/supplier.html Country State GST Type and GSTIN fields, frontend/static/script/js/modules/js/suppliers.js state loading GST-field visibility GSTIN validation and prefix-to-state behavior, frontend/static/script/js/modules/js/receiving_add.js supplier identity fill save edit and purchase preview, api/src/models/receiving.model.js GSTIN-first inter/intra-state decision and supplier tax identity persistence, frontend/static/script/js/modules/js/report_gstrtwo.js and report_gstrtwob.js supplier GST report classification

Set supplier location firstChoose the legal supplier country and state from the invoice; GST Fields are available when India GST is enabled.
Verify the saved supplierThe supplier profile exposes its saved tax classification beside contact details and recent purchases.
Reconcile tax after purchasingTax reports depend on saved purchase tax components and supplier identity; review them with source invoices.

Create or Correct the Supplier

  1. Open Purchase -> Supplier List and select New, or select an existing supplier and Edit.
  2. Enter the legal supplier name and useful contact details from controlled records.
  3. Choose the supplier's Country and State from the invoice address or registration evidence.
  4. When India GST is enabled, expand GST Fields.
  5. Choose Unregistered - consumer, Registered - Regular or Registered - Composite according to evidence.
  6. For a registered type, enter the exact uppercase 15-character GSTIN.
  7. Confirm the state after entry; a recognized first-two-digit GST state code can update it automatically.
  8. Save, reopen the supplier profile and verify the tax type before recording a live purchase.

How Posnic Uses State and GSTIN

ConditionInter/intra-state sourcePurchase tax result
GSTIN is valid and matches the 15-character patternFirst two GSTIN digits are compared with the current branch state code.Different codes route saved item tax to IGST; matching codes split it equally into CGST and SGST.
GSTIN is absent or not validSupplier state text is compared with current branch state.Different state text routes tax to IGST; matching text splits CGST and SGST.
India GST is not enabledIndia inter/intra split is not applied by this purchase path.Use the shop's configured tax system and local accounting rules.
Supplier identity changes laterEach purchase stores the supplier identity submitted with that document.Correct future supplier setup and review historical purchases separately.

Validate the GSTIN

  • Posnic requires exactly 15 characters for registered supplier types.
  • The accepted structure is two digits, five uppercase letters, four digits, one uppercase letter, one alphanumeric entity character, Z and one final alphanumeric checksum character.
  • Format validation does not prove that the registration belongs to this supplier or is currently active.
  • Compare legal name, GSTIN, state and invoice address with authoritative supplier evidence.
  • Never change state merely to force IGST or CGST/SGST totals to look convenient.

Verify on the First Purchase

  1. Use one simple supplier invoice with a known tax rate and legal supplier identity.
  2. Open New Purchase and select the saved supplier; Posnic fills state, GST type and GSTIN into the purchase data.
  3. Confirm the supplier shown is the intended legal entity, not a similarly named contact.
  4. Add one item and apply the approved purchase tax treatment.
  5. Compare the expected IGST or CGST/SGST split with branch state and supplier GSTIN state code.
  6. Check subtotal, tax, charges and supplier-declared invoice total before saving.
  7. Attach the invoice, save once, reopen the purchase and review its supplier/tax identity.
  8. Run the relevant purchase register, Tax Summary or GSTR working report for the same period.

Regular vs Composition Reporting

TypeOperator controlReporting caution
RegularRecord valid GSTIN, state and invoice tax exactly.Regular supplier purchases are used in registered-supplier GST report paths; verify ITC separately.
CompositeRecord valid GSTIN and confirm invoice classification.Composition purchase reporting has separate treatment; do not assume normal input credit.
UnregisteredKeep type consumer/unregistered and retain invoice identity.Do not manufacture a registered purchase by entering another party's GSTIN.
Wrong or stale typeCorrect the supplier before future purchases and review affected documents.Changing the supplier master alone does not prove historical reports were corrected.

Correct a Supplier Tax-Identity Error

  1. Preserve the original invoice and identify every affected purchase number and reporting period.
  2. Compare supplier legal name, state, GST type and GSTIN with authoritative evidence.
  3. Edit the supplier master for future use only after approval.
  4. Open each editable affected purchase and confirm its stored supplier identity and tax split.
  5. Correct the purchase only through the approved edit, return, void or accounting process; do not overwrite evidence.
  6. Recheck Exclusive Tax and Input credit claimable because those controls answer different questions.
  7. Rerun purchase and GST reports and document any closed-period adjustment with the accountant.

Troubleshooting and Controls

ProblemLikely reasonControlled response
GST Fields are not visibleIndia GST is not enabled for the shop or the accordion is collapsed.Verify Tax settings, then expand GST Fields; do not force hidden values through another field.
GSTIN field appearsA registered GST type was selected.Enter a verified 15-character GSTIN or select the correct unregistered type.
GSTIN is rejectedLength, uppercase structure or pattern is invalid.Compare character by character with legal evidence; do not pad or invent characters.
State changes while typing GSTINThe first two digits matched Posnic's GST state map.Confirm the new state agrees with the invoice and registration before saving.
Purchase shows IGST unexpectedlyValid GSTIN state code differs from branch state, or fallback supplier state differs.Verify both branch and supplier identity before changing tax values.
Purchase shows CGST/SGST unexpectedlySupplier and branch resolve to the same state.Check GSTIN prefixes and branch state against evidence.
Supplier profile is correct but old report is wrongHistorical purchase retained earlier identity or tax values.Audit affected purchase documents; master-data correction alone is insufficient.

Supplier GST Checklist

  • Legal supplier name and invoice address agree.
  • Country and state match registration evidence.
  • GST type reflects current legal status.
  • Registered GSTIN is exact, validly formatted and belongs to the supplier.
  • First purchase produces the expected IGST or CGST/SGST classification.
  • ITC eligibility is reviewed separately for each purchase.
  • Purchase and GST reports reconcile to source invoices.

Related Manual Pages

Purchase Supplier Setup Supplier setup is the address book for purchasing. Clean names, phone numbers, addresses and tax identity make purchase orders, reports and supplier follow-up reliable. Purchase Supplier Profile The supplier profile is the purchasing memory for a vendor: contact details, purchase totals, recent bills and document preview all sit beside the supplier list. Purchase Receive Stock Receiving is the point where purchased goods become trusted stock. The operator must match supplier, quantity, cost, invoice total, tax and proof before saving. Purchase Purchase Exclusive Tax Exclusive Tax controls whether configured exclusive item tax is added above purchase cost. In the current receiving flow, clearing it sets line tax to zero rather than extracting included tax from the entered price. Purchase Input Credit Eligibility The purchase eligibility checkbox controls whether saved purchase tax enters Posnic's Tax Payable input-credit calculation. It does not change tax rates, item cost, stock or the supplier invoice. Purchase Invoice Total Mismatch Posnic compares the supplier's declared tax-inclusive invoice total with its calculated purchase total. A difference above 0.50 is saved as a visible warning instead of blocking received stock. Settings Tax Regime & Defaults Set the legal tax behavior first, then choose whether new catalog items should inherit a default rate. Reports GSTR-2A Purchase Review Posnic derives this screen from its own receiving and supplier records. It does not download the government's dynamic GSTR-2A statement. Reports GSTR-2B ITC Review The Posnic GSTR-2B-style screen uses internal receiving data. Eligibility and the official static statement must be verified outside Posnic before credit is claimed. Reports Tax Payable Tax Payable is the deeper accounting control. It applies purchase ITC eligibility, calculates monthly payable or carried credit and exposes the supplier documents behind the input total.