diff --git a/boot/modules/acquiring/src/test/java/com/klaro/acquirecore/acquiring/service/TxMessageReceiveServiceTest.java b/boot/modules/acquiring/src/test/java/com/klaro/acquirecore/acquiring/service/TxMessageReceiveServiceTest.java
new file mode 100644
index 0000000..9f46778
--- /dev/null
+++ b/boot/modules/acquiring/src/test/java/com/klaro/acquirecore/acquiring/service/TxMessageReceiveServiceTest.java
@@ -0,0 +1,158 @@
+package com.klaro.acquirecore.acquiring.service;
+
+import com.klaro.acquirecore.acquiring.dto.TxMessage;
+import com.klaro.acquirecore.acquiring.dto.TxResult;
+import com.klaro.acquirecore.acquiring.repository.TxRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class TxMessageReceiveServiceTest {
+
+    @Mock
+    private TxRepository txRepository;
+
+    private TxMessageCodec codec;
+    private TxMessageReceiveService service;
+
+    @BeforeEach
+    void setUp() {
+        codec = new TxMessageCodec(new com.fasterxml.jackson.databind.ObjectMapper());
+        service = new TxMessageReceiveService(codec, txRepository);
+    }
+
+    @Test
+    void receive_validApprovalMessage_returnsSuccess() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "M001", "T001", "10000");
+        when(txRepository.isMerchantActive("M001")).thenReturn(true);
+        when(txRepository.isTerminalActive("M001", "T001")).thenReturn(true);
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertTrue(result.isSuccess());
+        assertEquals("0000", result.getCode());
+        verify(txRepository).saveTransaction(any(TxMessage.class));
+    }
+
+    @Test
+    void receive_missingMerchantId_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "", "T001", "10000");
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("1001", result.getCode());
+    }
+
+    @Test
+    void receive_missingTerminalId_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "M001", "", "10000");
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("1002", result.getCode());
+    }
+
+    @Test
+    void receive_invalidAmount_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "M001", "T001", "invalid");
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("1004", result.getCode());
+    }
+
+    @Test
+    void receive_inactiveMerchant_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "M001", "T001", "10000");
+        when(txRepository.isMerchantActive("M001")).thenReturn(false);
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("2001", result.getCode());
+    }
+
+    @Test
+    void receive_inactiveTerminal_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("REQ", "M001", "T001", "10000");
+        when(txRepository.isMerchantActive("M001")).thenReturn(true);
+        when(txRepository.isTerminalActive("M001", "T001")).thenReturn(false);
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("2002", result.getCode());
+    }
+
+    @Test
+    void receive_cancelMessage_callsCancellation() {
+        // Given
+        byte[] raw = buildRawMessage("CANCEL", "M001", "T001", "10000");
+        when(txRepository.isMerchantActive("M001")).thenReturn(true);
+        when(txRepository.isTerminalActive("M001", "T001")).thenReturn(true);
+        when(txRepository.transactionExists(anyString())).thenReturn(true);
+        when(txRepository.getTransactionStatus(anyString())).thenReturn("APPROVED");
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertTrue(result.isSuccess());
+        verify(txRepository).updateTransactionStatus(anyString(), eq("CANCELLED"));
+    }
+
+    @Test
+    void receive_cancelNonExistentTransaction_returnsError() {
+        // Given
+        byte[] raw = buildRawMessage("CANCEL", "M001", "T001", "10000");
+        when(txRepository.isMerchantActive("M001")).thenReturn(true);
+        when(txRepository.isTerminalActive("M001", "T001")).thenReturn(true);
+        when(txRepository.transactionExists(anyString())).thenReturn(false);
+
+        // When
+        TxResult result = service.receive(raw);
+
+        // Then
+        assertFalse(result.isSuccess());
+        assertEquals("3001", result.getCode());
+    }
+
+    private byte[] buildRawMessage(String status, String merchantId, String terminalId, String amount) {
+        String body = String.format(
+                "{\"STATUS\":\"%s\",\"MERCHANTID\":\"%s\",\"TERMINALID\":\"%s\",\"AMOUNT\":\"%s\"}",
+                status, merchantId, terminalId, amount);
+        String header = String.format("%-20s", "TXMSG");
+        return (header + body).getBytes(StandardCharsets.ISO_8859_1);
+    }
+}