diff --git a/finance/src/test/java/com/baiyue/finance/BusinessFeeSourceEventServiceTest.java b/finance/src/test/java/com/baiyue/finance/BusinessFeeSourceEventServiceTest.java
index b1967442e..a997a3a92 100644
--- a/finance/src/test/java/com/baiyue/finance/BusinessFeeSourceEventServiceTest.java
+++ b/finance/src/test/java/com/baiyue/finance/BusinessFeeSourceEventServiceTest.java
@@ -164,4 +164,77 @@ class BusinessFeeSourceEventServiceTest {
             null, base.traceId(), "LASTLEG:FEE:701:" + version, null, payload,
             EventPayloadHash.sha256(EventPayloadCanonicalizer.canonicalize(payload)));
     }
+
+    @Test
+    void sameEventIdWithDifferentPayloadIsRejectedWithoutWrites() {
+        var event = payableEvent("PUBLISHED", 1);
+        when(jdbc.queryForList(startsWith("SELECT payload_hash,status"), eq("LASTLEG"), eq(event.eventId())))
+            .thenReturn(List.of(Map.of("payload_hash", "different", "status", "PROCESSED", "result_resource_id", 901L)));
+        assertThatThrownBy(() -> service.consume(event)).hasMessageContaining("同一事件ID");
+        verify(jdbc, never()).update(anyString(), any(Object[].class));
+    }
+
+    @Test
+    void sameSourceVersionWithDifferentHashCannotOverwriteCost() {
+        var event = payableEvent("PUBLISHED", 1);
+        existingVersion("different", "AVAILABLE");
+        assertThatThrownBy(() -> service.consume(event)).hasMessageContaining("同一来源版本");
+        noFinancialWrites();
+    }
+
+    @Test
+    void voidedSourceCannotBeRevivedByPublicationReplay() {
+        var event = payableEvent("PUBLISHED", 1);
+        existingVersion(event.payload().get("sourceHash").asText(), "VOIDED");
+        assertThat(service.consume(event)).isEqualTo(901L);
+        noFinancialWrites();
+    }
+
+    @Test
+    void voidTargetsOnlyMatchingOverseasCostVersion() {
+        var event = payableEvent("VOIDED", 1);
+        existingVersion(event.payload().get("sourceHash").asText(), "AVAILABLE");
+        assertThat(service.consume(event)).isEqualTo(901L);
+        verify(jdbc).update(startsWith("UPDATE fin_cost SET status='VOIDED'"),
+            eq("LASTLEG"), eq("OVERSEAS_CONTAINER_FEE"), eq(701L), eq(1));
+        verify(jdbc, never()).update(startsWith("INSERT INTO fin_cost"), any(Object[].class));
+    }
+
+    @Test
+    void frozenSourceRejectsAdjustmentWithoutReplacingSourceOrCost() {
+        var event = payableEvent("ADJUSTED", 2);
+        when(jdbc.queryForObject(startsWith("SELECT COUNT(*) FROM fin_fee_source f WHERE f.source_system=?"),
+            eq(Integer.class), eq("LASTLEG"), eq("OVERSEAS_CONTAINER_FEE"), eq(701L))).thenReturn(1);
+        assertThatThrownBy(() -> service.consume(event)).hasMessageContaining("禁止调整或替代");
+        noFinancialWrites();
+    }
+
+    @Test
+    void frozenSourceRejectsVoidWithoutChangingSourceOrCost() {
+        var event = payableEvent("VOIDED", 1);
+        existingVersion(event.payload().get("sourceHash").asText(), "AVAILABLE");
+        when(jdbc.queryForObject(startsWith("SELECT COUNT(*) FROM fin_fee_source f WHERE f.id=?"),
+            eq(Integer.class), eq(901L))).thenReturn(1);
+        assertThatThrownBy(() -> service.consume(event)).hasMessageContaining("禁止作废");
+        noFinancialWrites();
+    }
+
+    private EventEnvelope payableEvent(String action, int version) {
+        when(suppliers.requireActive(71L, null)).thenReturn(
+            new com.baiyue.finance.client.WarehouseSupplierClient.SupplierSnapshot(71L, "供应商", null, "ACTIVE"));
+        return containerEvent("CNY", "61", action, version);
+    }
+
+    private void existingVersion(String hash, String status) {
+        when(jdbc.queryForList(startsWith("SELECT id,source_hash,status FROM fin_fee_source"),
+            eq("LASTLEG"), eq("OVERSEAS_CONTAINER_FEE"), eq(701L), eq(1)))
+            .thenReturn(List.of(Map.of("id", 901L, "source_hash", hash, "status", status)));
+    }
+
+    private void noFinancialWrites() {
+        verify(jdbc, never()).update(startsWith("INSERT INTO fin_fee_source"), any(Object[].class));
+        verify(jdbc, never()).update(startsWith("UPDATE fin_fee_source"), any(Object[].class));
+        verify(jdbc, never()).update(startsWith("INSERT INTO fin_cost"), any(Object[].class));
+        verify(jdbc, never()).update(startsWith("UPDATE fin_cost"), any(Object[].class));
+    }
 }