diff --git a/migration/iD10/oracle/202210111536_IDEMPIERE-5447.sql b/migration/iD10/oracle/202210111536_IDEMPIERE-5447.sql
new file mode 100644
index 0000000000..bdc7444344
--- /dev/null
+++ b/migration/iD10/oracle/202210111536_IDEMPIERE-5447.sql
@@ -0,0 +1,10 @@
+-- IDEMPIERE-5447 Add unit test for Merge form
+SELECT register_migration_script('202210111536_IDEMPIERE-5447.sql') FROM dual;
+
+SET SQLBLANKLINES ON
+SET DEFINE OFF
+
+-- Oct 11, 2022, 3:36:36 PM CEST
+UPDATE AD_Menu SET PredefinedContextVariables='IgnoreIsSOTrxInBPInfo=Y',Updated=TO_TIMESTAMP('2022-10-11 15:36:36','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Menu_ID=397
+;
+
diff --git a/migration/iD10/postgresql/202210111536_IDEMPIERE-5447.sql b/migration/iD10/postgresql/202210111536_IDEMPIERE-5447.sql
new file mode 100644
index 0000000000..8ad357683b
--- /dev/null
+++ b/migration/iD10/postgresql/202210111536_IDEMPIERE-5447.sql
@@ -0,0 +1,7 @@
+-- IDEMPIERE-5447 Add unit test for Merge form
+SELECT register_migration_script('202210111536_IDEMPIERE-5447.sql') FROM dual;
+
+-- Oct 11, 2022, 3:36:36 PM CEST
+UPDATE AD_Menu SET PredefinedContextVariables='IgnoreIsSOTrxInBPInfo=Y',Updated=TO_TIMESTAMP('2022-10-11 15:36:36','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Menu_ID=397
+;
+
diff --git a/org.adempiere.base/src/org/compiere/model/MBPartner.java b/org.adempiere.base/src/org/compiere/model/MBPartner.java
index dca783c33c..0c32503acd 100644
--- a/org.adempiere.base/src/org/compiere/model/MBPartner.java
+++ b/org.adempiere.base/src/org/compiere/model/MBPartner.java
@@ -625,7 +625,7 @@ public class MBPartner extends X_C_BPartner implements ImmutablePOSupport
 	}	//	getAD_OrgBP_ID_Int
 
 	/**
-	 * 	Get Primary C_BPartner_Location_ID
+	 * 	Get Primary C_BPartner_Location_ID (BillTo or First)
 	 *	@return C_BPartner_Location_ID
 	 */
 	public int getPrimaryC_BPartner_Location_ID()
@@ -651,7 +651,7 @@ public class MBPartner extends X_C_BPartner implements ImmutablePOSupport
 	}	//	getPrimaryC_BPartner_Location_ID
 	
 	/**
-	 * 	Get Primary C_BPartner_Location
+	 * 	Get Primary C_BPartner_Location (BillTo or First)
 	 *	@return C_BPartner_Location
 	 */
 	public MBPartnerLocation getPrimaryC_BPartner_Location()
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/form/WMerge.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/form/WMerge.java
index aa7be86680..ba9c30dfac 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/form/WMerge.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/form/WMerge.java
@@ -235,8 +235,9 @@ public class WMerge extends Merge implements IFormController, EventListener<Even
 					to_Info = m_to[i].getDisplay ();
 				}
 			}
-		}	//	get first merge pair
+		}
 
+		//process first merge pair, ignore the rest
 		if (from_ID == 0 || from_ID == to_ID)
 			return;
 
@@ -253,8 +254,6 @@ public class WMerge extends Merge implements IFormController, EventListener<Even
 			{
 				if (result)
 				{
-					updateDeleteTable(columnNameRef);
-
 					Clients.showBusy("");
 					runnable = new MergeRunnable(columnNameRef, fromIdRef, toIdRef);
 					Clients.response(new AuEcho(form, "runProcess", null));
@@ -264,7 +263,7 @@ public class WMerge extends Merge implements IFormController, EventListener<Even
 		});				
 	}   //  actionPerformed
 	
-	class MergeRunnable implements Runnable {
+	private class MergeRunnable implements Runnable {
 		private int to_ID;
 		private int from_ID;
 		private String columnName;
@@ -285,11 +284,17 @@ public class WMerge extends Merge implements IFormController, EventListener<Even
 		}		
 	}
 
+	/**
+	 * execute merge, call from echo event
+	 */
 	public void runProcess() 
 	{
 		runnable.run();
 	}
 	
+	/**
+	 * clean up, call form echo event
+	 */
 	public void onAfterProcess() 
 	{
 		if (m_success)
@@ -306,8 +311,9 @@ public class WMerge extends Merge implements IFormController, EventListener<Even
 		dispose();
 	}
 
+	@Override
 	public ADForm getForm() 
 	{
 		return form;
 	}
-}	//	VMerge
+}
diff --git a/org.adempiere.ui/src/org/compiere/apps/form/Merge.java b/org.adempiere.ui/src/org/compiere/apps/form/Merge.java
index 8dc0f5da9f..f6a7844b9d 100644
--- a/org.adempiere.ui/src/org/compiere/apps/form/Merge.java
+++ b/org.adempiere.ui/src/org/compiere/apps/form/Merge.java
@@ -29,16 +29,14 @@ import org.compiere.util.Trx;
 public class Merge 
 {
 	/**	Window No			*/
-	public int         	m_WindowNo = 0;
+	protected int         	m_WindowNo = 0;
 	/**	Total Count			*/
-	public int				m_totalCount = 0;
+	protected int				m_totalCount = 0;
 	/** Error Log			*/
-	public StringBuffer	m_errorLog = new StringBuffer();
-	/**	Connection			*/
-	//private Connection		m_con = null;
+	protected StringBuffer	m_errorLog = new StringBuffer();
 	private Trx 			m_trx = null;         
 	/**	Logger			*/
-	public static final CLogger log = CLogger.getCLogger(Merge.class);
+	protected static final CLogger log = CLogger.getCLogger(Merge.class);
 
 	public static String	AD_ORG_ID = "AD_Org_ID";
 	public static String	C_BPARTNER_ID = "C_BPartner_ID";
@@ -46,26 +44,30 @@ public class Merge
 	public static String	M_PRODUCT_ID = "M_Product_ID";
 
 	/** Tables to delete (not update) for AD_Org	*/
-	public static String[]	s_delete_Org = new String[]
+	protected static String[]	s_delete_Org = new String[]
 		{"AD_OrgInfo", "AD_Role_OrgAccess"};
 	/** Tables to delete (not update) for AD_User	*/
-	public static String[]	s_delete_User = new String[]
+	protected static String[]	s_delete_User = new String[]
 		{"AD_User_Roles"};
 	/** Tables to delete (not update) for C_BPartner	*/
-	public static String[]	s_delete_BPartner = new String[]
+	protected static String[]	s_delete_BPartner = new String[]
 		{"C_BP_Employee_Acct", "C_BP_Vendor_Acct", "C_BP_Customer_Acct", 
 		"T_Aging"};
 	/** Tables to delete (not update) for M_Product		*/
-	public static String[]	s_delete_Product = new String[]
+	protected static String[]	s_delete_Product = new String[]
 		{"M_Product_PO", "M_Replenish", "T_Replenish", 
 		"M_ProductPrice", 
 		"M_Cost", // teo_sarca [ 1704554 ]
-		"M_Product_Trl", "M_Product_Acct"};		//	M_Storage
+		"M_Product_Trl", "M_Product_Acct"};
 
-	public String[]	m_columnName = null;
-	public String[]	m_deleteTables = null;
+	protected String[]	m_columnName = null;
+	protected String[]	m_deleteTables = null;
 	
-	public void updateDeleteTable(String columnName)
+	/**
+	 * Determine the list of tables to delete records from columnName 
+	 * @param columnName
+	 */
+	protected void updateDeleteTable(String columnName)
 	{
 		//	** Update **
 		if (columnName.equals(AD_ORG_ID))
@@ -81,7 +83,7 @@ public class Merge
 
 	/**
 	 * 	Merge.
-	 *	@param ColumnName column
+	 *	@param ColumnName ID column (M_Product_ID, AD_Org_ID, C_BPartner_ID or AD_User_ID)
 	 *	@param from_ID from
 	 *	@param to_ID to
 	 *	@return true if merged
@@ -92,6 +94,8 @@ public class Merge
 		if (log.isLoggable(Level.CONFIG)) log.config(ColumnName
 			+ " - From=" + from_ID + ",To=" + to_ID);
 
+		updateDeleteTable(ColumnName);
+		
 		boolean success = true;
 		m_totalCount = 0;
 		m_errorLog = new StringBuffer();
@@ -140,7 +144,7 @@ public class Merge
 			{
 				sql = "DELETE FROM " + TableName + " WHERE " + ColumnName + "=" + from_ID;
 				
-				if ( DB.executeUpdate(sql, m_trx.getTrxName()) < 0 )
+				if ( DB.executeUpdateEx(sql, m_trx.getTrxName()) < 0 )
 				{
 					m_errorLog.append(Env.NL).append("DELETE FROM ").append(TableName)
 					.append(" - ");
@@ -184,7 +188,7 @@ public class Merge
 	 * 	@param to_ID to
 	 * 	@return -1 for error or number of changes
 	 */
-	public int mergeTable (String TableName, String ColumnName, int from_ID, int to_ID)
+	protected int mergeTable (String TableName, String ColumnName, int from_ID, int to_ID)
 	{
 		if (log.isLoggable(Level.FINE)) log.fine(TableName + "." + ColumnName + " - From=" + from_ID + ",To=" + to_ID);
 		String sql = "UPDATE " + TableName
@@ -208,7 +212,7 @@ public class Merge
 				+ " AND " + X_M_Cost.COLUMNNAME_CumulatedQty + "=0";
 		}
 
-		int count = DB.executeUpdate(sql, m_trx.getTrxName());
+		int count = DB.executeUpdateEx(sql, m_trx.getTrxName());
 		if (count < 0)
 		{
 			count = -1;
diff --git a/org.idempiere.test/src/org/idempiere/test/form/MergeFormTest.java b/org.idempiere.test/src/org/idempiere/test/form/MergeFormTest.java
new file mode 100644
index 0000000000..a5497c9635
--- /dev/null
+++ b/org.idempiere.test/src/org/idempiere/test/form/MergeFormTest.java
@@ -0,0 +1,269 @@
+/***********************************************************************
+ * This file is part of iDempiere ERP Open Source                      *
+ * http://www.idempiere.org                                            *
+ *                                                                     *
+ * Copyright (C) Contributors                                          *
+ *                                                                     *
+ * This program is free software; you can redistribute it and/or       *
+ * modify it under the terms of the GNU General Public License         *
+ * as published by the Free Software Foundation; either version 2      *
+ * of the License, or (at your option) any later version.              *
+ *                                                                     *
+ * This program is distributed in the hope that it will be useful,     *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of      *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the        *
+ * GNU General Public License for more details.                        *
+ *                                                                     *
+ * You should have received a copy of the GNU General Public License   *
+ * along with this program; if not, write to the Free Software         *
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,          *
+ * MA 02110-1301, USA.                                                 *
+ *                                                                     *
+ * Contributors:                                                       *
+ * - hengsin                         								   *
+ **********************************************************************/
+package org.idempiere.test.form;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.math.BigDecimal;
+
+import org.compiere.apps.form.Merge;
+import org.compiere.model.MBPartner;
+import org.compiere.model.MBPartnerLocation;
+import org.compiere.model.MLocation;
+import org.compiere.model.MOrder;
+import org.compiere.model.MOrderLine;
+import org.compiere.model.MPriceList;
+import org.compiere.model.MPriceListVersion;
+import org.compiere.model.MProduct;
+import org.compiere.model.MProductPrice;
+import org.compiere.model.MUser;
+import org.compiere.model.MUserDefWin;
+import org.compiere.model.PO;
+import org.compiere.model.SystemIDs;
+import org.compiere.util.Env;
+import org.idempiere.test.AbstractTestCase;
+import org.idempiere.test.DictionaryIDs;
+import org.junit.jupiter.api.Test;
+
+/**
+ * 
+ * @author hengsin
+ *
+ */
+public class MergeFormTest extends AbstractTestCase {
+
+	public MergeFormTest() {
+	}
+
+	@Test
+	public void testMergeProduct() {
+
+		MProduct p1 = null;
+		MProduct p2 = null;
+		MProductPrice pp1 = null;
+		MProductPrice pp2 = null;
+		MOrder order1 = null;
+		MOrderLine ol1 = null;
+		MOrder order2 = null;
+		MOrderLine ol2 = null;
+		
+		try {
+
+			p1 = new MProduct(Env.getCtx(), 0, null);
+			p1.setName("testMergeProduct1");
+			p1.setM_Product_Category_ID(DictionaryIDs.M_Product_Category.STANDARD.id);
+			p1.setProductType(MProduct.PRODUCTTYPE_Item);
+			p1.setIsStocked(false);
+			p1.setC_UOM_ID(DictionaryIDs.C_UOM.EACH.id);
+			p1.setC_TaxCategory_ID(DictionaryIDs.C_TaxCategory.STANDARD.id);
+			p1.saveEx();
+
+			p2 = new MProduct(Env.getCtx(), 0, null);
+			p2.setName("testMergeProduct2");
+			p2.setM_Product_Category_ID(DictionaryIDs.M_Product_Category.STANDARD.id);
+			p2.setProductType(MProduct.PRODUCTTYPE_Item);
+			p2.setIsStocked(false);
+			p2.setC_UOM_ID(DictionaryIDs.C_UOM.EACH.id);
+			p2.setC_TaxCategory_ID(DictionaryIDs.C_TaxCategory.STANDARD.id);
+			p2.saveEx();
+
+			MPriceList pl = MPriceList.get(DictionaryIDs.M_PriceList.STANDARD.id);
+			MPriceListVersion plv = pl.getPriceListVersion(null);
+			pp1 = new MProductPrice(Env.getCtx(), 0, null);
+			pp1.setM_PriceList_Version_ID(plv.get_ID());
+			pp1.setM_Product_ID(p1.getM_Product_ID());
+			pp1.setPrices(new BigDecimal("1"), new BigDecimal("1"), new BigDecimal("1"));
+			pp1.saveEx();
+
+			pp2 = new MProductPrice(Env.getCtx(), 0, null);
+			pp2.setM_PriceList_Version_ID(plv.get_ID());
+			pp2.setM_Product_ID(p2.getM_Product_ID());
+			pp2.setPrices(new BigDecimal("1"), new BigDecimal("1"), new BigDecimal("1"));
+			pp2.saveEx();
+
+			order1 = new MOrder(Env.getCtx(), 0, null);
+			order1.setIsSOTrx(true);
+			order1.setC_DocTypeTarget_ID();
+			order1.setBPartner(MBPartner.get(Env.getCtx(), DictionaryIDs.C_BPartner.JOE_BLOCK.id));
+			order1.saveEx();
+
+			ol1 = new MOrderLine(order1);
+			ol1.setM_Product_ID(p1.get_ID());
+			ol1.setQty(new BigDecimal("1"));
+			ol1.saveEx();
+
+			order2 = new MOrder(Env.getCtx(), 0, null);
+			order2.setIsSOTrx(true);
+			order2.setC_DocTypeTarget_ID();
+			order2.setBPartner(MBPartner.get(Env.getCtx(), DictionaryIDs.C_BPartner.JOE_BLOCK.id));
+			order2.saveEx();
+
+			ol2 = new MOrderLine(order1);
+			ol2.setM_Product_ID(p2.get_ID());
+			ol2.setQty(new BigDecimal("1"));
+			ol2.saveEx();
+
+			Merge merge = new Merge();
+			boolean ok = merge.merge(Merge.M_PRODUCT_ID, p1.get_ID(), p2.get_ID());
+			assertTrue(ok, "Merge fail");
+			ol1.load(null);
+			assertEquals(p2.get_ID(), ol1.getM_Product_ID(), "Unexpected order line M_Product_ID after merge");
+			ol2.load(null);
+			assertEquals(p2.get_ID(), ol2.getM_Product_ID(), "Unexpected order line M_Product_ID after merge");
+			pp1.load(null);
+			assertEquals(0, pp1.get_ID(), "Product Price not deleted after merge");
+			p1.load(null);
+			assertEquals(0, p1.get_ID(), "Product not deleted after merge");
+		} finally {
+			if (pp1 != null && pp1.get_ID() > 0)
+				pp1.deleteEx(true);
+			if (pp2 != null && pp2.get_ID() > 0)
+				pp2.deleteEx(true);
+			if (ol1 != null && ol1.get_ID() > 0)
+				ol1.deleteEx(true);
+			if (ol2 != null && ol2.get_ID() > 0)
+				ol2.deleteEx(true);
+			if (order1 != null && order1.get_ID() > 0)
+				order1.deleteEx(true);
+			if (order2 != null && order2.get_ID() > 0)
+				order2.deleteEx(true);
+			if (p1 != null && p1.get_ID() > 0)
+				p1.deleteEx(true);
+			if (p2 != null && p2.get_ID() > 0)
+				p2.deleteEx(true);
+		}
+	}
+	
+	@Test
+	public void testMergeBPartner() {
+		MBPartner bp1 = null;
+		MBPartner bp2 = null;
+		MOrder o1 = null;
+		MOrder o2 = null;
+		try {
+			MBPartner jb = MBPartner.get(Env.getCtx(), DictionaryIDs.C_BPartner.JOE_BLOCK.id);
+			MBPartnerLocation bpl = jb.getPrimaryC_BPartner_Location();
+			MLocation loc = new MLocation(Env.getCtx(), bpl.getC_Location_ID(), null);
+			
+			bp1 = new MBPartner(Env.getCtx(), 0, null);
+			bp1.setName("testMergeBPartner1");
+			bp1.setIsCustomer(true);
+			bp1.setC_BP_Group_ID(jb.getC_BP_Group_ID());
+			bp1.saveEx();
+			MLocation loc1 = new MLocation(Env.getCtx(), 0, null);
+			PO.copyValues(loc, loc1);
+			loc1.saveEx();
+			MBPartnerLocation bpl1 = new MBPartnerLocation(bp1);
+			bpl1.setC_Location_ID(loc1.get_ID());
+			bpl1.setIsShipTo(true);
+			bpl1.setIsBillTo(true);
+			bpl1.saveEx();
+			
+			bp2 = new MBPartner(Env.getCtx(), 0, null);
+			bp2.setName("testMergeBPartner2");
+			bp2.setIsCustomer(true);
+			bp2.setC_BP_Group_ID(bp1.getC_BP_Group_ID());
+			bp2.saveEx();
+			MLocation loc2 = new MLocation(Env.getCtx(), 0, null);
+			PO.copyValues(loc, loc2);
+			loc2.saveEx();
+			MBPartnerLocation bpl2 = new MBPartnerLocation(bp2);
+			bpl2.setC_Location_ID(loc2.get_ID());
+			bpl2.setIsShipTo(true);
+			bpl2.setIsBillTo(true);
+			bpl2.saveEx();
+			
+			o1 = new MOrder(Env.getCtx(), 0, null);
+			o1.setIsSOTrx(true);
+			o1.setC_DocTypeTarget_ID();
+			o1.setBPartner(bp1);
+			o1.saveEx();
+			
+			o2 = new MOrder(Env.getCtx(), 0, null);
+			o2.setIsSOTrx(true);
+			o2.setC_DocTypeTarget_ID();
+			o2.setBPartner(bp2);
+			o2.saveEx();
+			
+			Merge merge = new Merge();
+			boolean ok = merge.merge(Merge.C_BPARTNER_ID, bp1.get_ID(), bp2.get_ID());
+			assertTrue(ok, "Merge fail");
+			o1.load(null);
+			assertEquals(bp2.get_ID(), o1.getC_BPartner_ID(), "Unexpected order line C_BPartner_ID after merge");
+			o2.load(null);
+			assertEquals(bp2.get_ID(), o2.getC_BPartner_ID(), "Unexpected order line C_BPartner_ID after merge");
+			bp1.load(null);
+			assertEquals(0, bp1.get_ID(), "BPartner not deleted after merge");
+		} finally {
+			if (o1 != null && o1.get_ID() > 0)
+				o1.deleteEx(true);
+			if (o2 != null && o2.get_ID() > 0)
+				o2.deleteEx(true);
+			if (bp1 != null && bp1.get_ID() > 0)
+				bp1.deleteEx(true);
+			if (bp2 != null && bp2.get_ID() > 0)
+				bp2.deleteEx(true);			
+		}
+	}
+	
+	@Test
+	public void testMergeUser() {
+		MUser u1 = null;
+		MUser u2 = null;
+		MUserDefWin udw = null;
+		
+		try {
+			u1 = new MUser(Env.getCtx(), 0, null);
+			u1.setName("testMergeUser1");
+			u1.saveEx();
+			
+			u2 = new MUser(Env.getCtx(), 0, null);
+			u2.setName("testMergeUser2");
+			u2.saveEx();
+			
+			udw = new MUserDefWin(Env.getCtx(), 0, null);
+			udw.setAD_User_ID(u1.get_ID());
+			udw.setAD_Window_ID(SystemIDs.WINDOW_SALES_ORDER);
+			udw.saveEx();
+			
+			Merge merge = new Merge();
+			boolean ok = merge.merge(Merge.AD_USER_ID, u1.get_ID(), u2.get_ID());
+			assertTrue(ok, "Merge fail");
+			
+			u1.load(null);
+			assertEquals(0, u1.get_ID(), "User not deleted after merge");
+			udw.load(null);
+			assertEquals(u2.get_ID(), udw.getAD_User_ID(), "Unexpected MUserDefWin.AD_User_ID after merge");
+		} finally {
+			if (udw != null && udw.get_ID() > 0)
+				udw.deleteEx(true);
+			if (u1 != null && u1.get_ID() > 0)
+				u1.deleteEx(true);
+			if (u2 != null && u2.get_ID() > 0)
+				u2.deleteEx(true);
+		}
+	}
+}