feat: allow itc claim period for RCM Purchase Invoice

india_compliance/gst_india/doctype/gstr_3b_report/test_gstr_3b_report.py

@@ -5,7 +5,7 @@
 
 import frappe
 from frappe.tests import IntegrationTestCase, change_settings
-from frappe.utils import get_month, getdate
+from frappe.utils import add_months, get_month, getdate
 
 from india_compliance.gst_india.doctype.bill_of_entry.bill_of_entry import (
     make_bill_of_entry,
@@ -18,6 +18,7 @@
     GSTR3B_Inward_Nil_Exempt,
 )
 from india_compliance.gst_india.utils import get_gst_accounts_by_type
+from india_compliance.gst_india.utils.itc_claim import format_period
 from india_compliance.gst_india.utils.tests import (
     append_item,
     create_purchase_invoice,
@@ -752,6 +753,63 @@ def test_inter_state_advance_payment_entry(self):
         self.assertEqual(output["sup_details"]["osup_det"]["camt"], 0.0)
         self.assertEqual(output["sup_details"]["osup_det"]["samt"], 0.0)
 
+    def test_rcm_outward_liability(self):
+        """RCM outward liability uses posting date while ITC uses claim period."""
+        today = getdate()
+        next_month = add_months(today, 1)
+        next_period = format_period(next_month)
+
+        pi = create_purchase_invoice(
+            supplier="_Test Unregistered Supplier",
+            is_reverse_charge=True,
+            is_in_state_rcm=True,
+            posting_date=today,
+            do_not_submit=True,
+        )
+        pi.itc_claim_period = next_period
+        pi.save()
+        pi.submit()
+
+        # -- Report for THIS month (filter_by ITC Claim Period) --
+        report_this = frappe.get_doc(
+            {
+                "doctype": "GSTR 3B Report",
+                "company": "_Test Indian Registered Company",
+                "company_gstin": "24AAQCA8719H1ZC",
+                "year": today.year,
+                "month_or_quarter": get_month(today),
+                "filter_by": "ITC Claim Period",
+            }
+        ).insert()
+        output = json.loads(report_this.json_output)
+
+        # Outward RCM liability always by posting date → invoice IS included
+        self.assertEqual(output["sup_details"]["isup_rev"]["txval"], 100.0)
+        # ITC by claim period → invoice is NOT included (deferred to next month)
+        itc_section = {r["ty"]: r for r in output["itc_elg"]["itc_avl"]}
+        self.assertEqual(itc_section.get("ISRC", {}).get("camt", 0.0), 0.0)
+        self.assertEqual(itc_section.get("ISRC", {}).get("samt", 0.0), 0.0)
+
+        # -- Report for NEXT month (filter_by ITC Claim Period) --
+        report_next = frappe.get_doc(
+            {
+                "doctype": "GSTR 3B Report",
+                "company": "_Test Indian Registered Company",
+                "company_gstin": "24AAQCA8719H1ZC",
+                "year": next_month.year,
+                "month_or_quarter": get_month(next_month),
+                "filter_by": "ITC Claim Period",
+            }
+        ).insert()
+        output = json.loads(report_next.json_output)
+
+        # Outward RCM by posting date → invoice is NOT in next month's liability
+        self.assertEqual(output["sup_details"]["isup_rev"]["txval"], 0.0)
+        # ITC by claim period → invoice IS in next month's ITC
+        itc_section = {r["ty"]: r for r in output["itc_elg"]["itc_avl"]}
+        self.assertEqual(itc_section.get("ISRC", {}).get("camt", 0.0), 9.0)
+        self.assertEqual(itc_section.get("ISRC", {}).get("samt", 0.0), 9.0)
+
 
 def create_sales_invoices():
     create_sales_invoice(is_in_state=True)

india_compliance/gst_india/overrides/test_purchase_invoice.py

@@ -272,39 +272,22 @@ def test_itc_claim_period_invalid_format(self):
 
     def test_itc_claim_period_for_unregistered_rcm(self):
         """
-        For Unregistered supplier RCM, ITC Claim Period must match the posting period
+        Unregistered RCM ITC Claim Period can be any valid period —
+        not restricted to the posting period.
         """
         pinv = create_purchase_invoice(
             supplier="_Test Unregistered Supplier",
             is_reverse_charge=True,
             do_not_submit=True,
         )
 
-        posting_period = format_period(pinv.posting_date)
-        self.assertEqual(pinv.itc_claim_period, posting_period)
-
-        # Try to change itc_claim_period to a different period - should fail
-        pinv.itc_claim_period = "012099"  # Different period
-
-        self.assertRaisesRegex(
-            frappe.exceptions.ValidationError,
-            re.compile(
-                r"ITC Claim Period must be .* for purchases from Unregistered suppliers under Reverse Charge"
-            ),
-            pinv.save,
-        )
-
-        # Try to set to "Deferred" - should also fail for Unregistered RCM
-        pinv.reload()
         pinv.itc_claim_period = ITC_CLAIM_PERIOD_DEFERRED
+        pinv.save()
+        self.assertEqual(pinv.itc_claim_period, ITC_CLAIM_PERIOD_DEFERRED)
 
-        self.assertRaisesRegex(
-            frappe.exceptions.ValidationError,
-            re.compile(
-                r"ITC Claim Period must be .* for purchases from Unregistered suppliers under Reverse Charge"
-            ),
-            pinv.save,
-        )
+        pinv.itc_claim_period = "012099"
+        pinv.save()
+        self.assertEqual(pinv.itc_claim_period, "012099")
 
     def test_itc_claim_period_deferred(self):
         """

india_compliance/gst_india/utils/gstr3b/gstr3b_outward_data.py

@@ -124,6 +124,7 @@ def is_inward_reverse_charge(self, invoice):
 class GSTR3BOutwardInvoices(GSTR3BCategoryConditions):
     def __init__(self, filters):
         self.filters = filters
+        self.filters.filter_by = "Posting Date"
         self.inward_query = GSTR3BInwardQuery(filters)
         self.gstr1_query = GSTR1Query(filters)
 

india_compliance/gst_india/utils/itc_claim.py

@@ -337,23 +337,18 @@ def _calculate_itc_claim_period(
     if inward_supply and inward_supply.get("return_period_2b"):
         default_period = _max_period(posting_period, inward_supply.return_period_2b)
 
-    if doc.get("gst_category") == "Unregistered" and doc.get("is_reverse_charge"):
-        return posting_period
-
     return _get_next_unfiled_period(doc.company_gstin, default_period, doc.posting_date, filed)
 
 
 def validate_itc_claim_period(doc) -> None:
     validate_mandatory_fields(doc, "itc_claim_period")
     _validate_period_format(doc.itc_claim_period)
-    _validate_itc_claim_period_for_rcm_invoice(doc)
     _validate_itc_claim_period_as_per_filing(doc)
 
 
 def validate_itc_claim_period_on_update_after_submit(doc) -> None:
     validate_mandatory_fields(doc, "itc_claim_period")
     _validate_period_format(doc.itc_claim_period)
-    _validate_itc_claim_period_for_rcm_invoice(doc)
 
     # On update-after-submit, period checks are needed only if period changed.
     previous = doc.get_doc_before_save()
@@ -386,22 +381,6 @@ def _validate_itc_claim_period_as_per_filing(doc) -> None:
         )
 
 
-def _validate_itc_claim_period_for_rcm_invoice(doc) -> None:
-    """For Unregistered RCM, ITC must be claimed in the same period as posting."""
-    if (
-        doc.doctype == "Purchase Invoice"
-        and doc.gst_category == "Unregistered"
-        and doc.is_reverse_charge
-        and doc.itc_claim_period != format_period(doc.posting_date)
-    ):
-        frappe.throw(
-            _(
-                "ITC Claim Period must be {0} (same as posting date) for purchases from"
-                " Unregistered suppliers under Reverse Charge."
-            ).format(format_period(doc.posting_date))
-        )
-
-
 # =============================================================================
 # Bulk Processing
 # =============================================================================

india_compliance/gst_india/utils/test_itc_claim.py

@@ -358,7 +358,7 @@ def test_calc_2b_period_earlier_than_posting(self):
         self.assertEqual(result, "032024")
 
     def test_calc_unregistered_rcm(self):
-        """Unregistered RCM always returns posting period."""
+        """Unregistered RCM follows same logic as regular invoices (next unfiled period)."""
         doc = self._make_doc(
             gst_category="Unregistered",
             is_reverse_charge=1,
@@ -367,6 +367,9 @@ def test_calc_unregistered_rcm(self):
         result = _calculate_itc_claim_period(doc, filed=set())
         self.assertEqual(result, "012024")
 
+        result = _calculate_itc_claim_period(doc, filed={"012024"})
+        self.assertEqual(result, "022024")
+
     def test_calc_no_inward_supply(self):
         """No inward supply → uses posting period as start."""
         doc = self._make_doc(posting_date=getdate("2024-01-15"))