diff --git a/PROMS/VEPROMS.CSLA.Library/Extension/ItemInsertExt.cs b/PROMS/VEPROMS.CSLA.Library/Extension/ItemInsertExt.cs
index e18920a4..1916f78f 100644
--- a/PROMS/VEPROMS.CSLA.Library/Extension/ItemInsertExt.cs
+++ b/PROMS/VEPROMS.CSLA.Library/Extension/ItemInsertExt.cs
@@ -539,6 +539,55 @@ namespace VEPROMS.CSLA.Library
 				return this;
 			}
 		}
+		// F2021-009 Get the number of children levels the passed in parent has
+		private static int GetMaxSubStepLevel(ItemInfo parent)
+		{
+			int maxStepLevel = parent.StepLevel-1; // subtract one to account for HLS - we want the sub-step level
+			foreach (ItemInfo kid in parent.Steps)
+			{
+				if (kid.Steps != null)
+					maxStepLevel = Math.Max(maxStepLevel, GetMaxSubStepLevel(kid));
+				else
+					maxStepLevel = Math.Max(maxStepLevel,kid.StepLevel-1); // subtract one to account for HLS because we are counting only sub-step levels
+			}
+			return maxStepLevel;
+		}
+		// F2021-009 Find the number of sub-step levels that the Copied Step has.
+		//           This is used to determin if the Paste will result in exesssive sub-step levels
+		private static int GetCopyStepMaxLevels(int copyStartID)
+		{
+			ItemInfo cpyItem = ItemInfo.Get(copyStartID);
+			return GetMaxSubStepLevel(cpyItem);
+		}
+		// F2021-009 Find the number of defined sequential tabs.  We use this to determin the number of defined sub-step levels
+		public int GetDefinedSubStepCount()
+		{
+			return GetDefinedSubStepCount(this);
+		}
+		// F2021-009 Find the number of defined sequential tabs.  We use this to determin the number of defined sub-step levels
+		public static int GetDefinedSubStepCount(ItemInfo curStep)
+		{
+			int cnt = 0;
+			cnt = curStep.ActiveFormat.PlantFormat.FormatData.SectData.StepSectionData.SeqTabFmtList.Count;
+			return cnt-1; // -1 to account for the high level step level
+		}
+		// F2021-009 for PROMS Express, display a message if the Paste of a CopyStep will results in sub-step levels
+		//           greater than what is defined in the format
+		public static bool PasteStepIsWithinDefinedSubStepLevels(int copyStartID, ItemInfo pasteTarget, bool doingReplace)
+		{
+			int largestSubStepLevel = GetCopyStepMaxLevels(copyStartID);
+			int numDefinedSubstepLevels = GetDefinedSubStepCount(pasteTarget);
+			largestSubStepLevel += (pasteTarget.StepLevel-((doingReplace)?1:0));// subtract one because HLS is level one, results in actual sub-step level
+			if (largestSubStepLevel > numDefinedSubstepLevels && pasteTarget.ActiveFormat.PlantFormat.FormatData.Express)
+			{
+				string mbMsg = "This will result with more sub-step levels than are defined in" +
+							 "\nthe format and could result in a step that is difficult to follow." +
+							 "\n\nConsider rewriting the step using less sub-steps levels.";
+				MessageBox.Show(mbMsg, "Paste Step Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+				return false;
+			}
+			return true;
+		}
 		// B2016-009 - added a message box explaining to the user that the copyed step will take on the destination type. 16-bit PROMS had also done this way.
 		//           - this one is used for Paste Replace with copyed step
 		public static void CheckSourceDestinationType(int copyStartID, ItemInfo itemInfo)