diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index ce09ce93b9..ccedb8e31d 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -819,7 +819,16 @@ CommandCost CmdInsertOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 			if (new_order.GetNonStopType() != ONSF_STOP_EVERYWHERE && !v->IsGroundVehicle()) return CMD_ERROR;
 			if (new_order.GetDepotOrderType() & ~(ODTFB_PART_OF_ORDERS | ((new_order.GetDepotOrderType() & ODTFB_PART_OF_ORDERS) != 0 ? ODTFB_SERVICE : 0))) return CMD_ERROR;
 			if (new_order.GetDepotActionType() & ~(ODATFB_HALT | ODATFB_NEAREST_DEPOT | ODATFB_UNBUNCH)) return CMD_ERROR;
-			if ((new_order.GetDepotOrderType() & ODTFB_SERVICE) && (new_order.GetDepotActionType() & ODATFB_HALT)) return CMD_ERROR;
+
+			/* Vehicles cannot have a "service if needed" order that also has a depot action. */
+			if ((new_order.GetDepotOrderType() & ODTFB_SERVICE) && (new_order.GetDepotActionType() & (ODATFB_HALT | ODATFB_UNBUNCH))) return CMD_ERROR;
+
+			/* Check if we're allowed to have a new unbunching order. */
+			if ((new_order.GetDepotActionType() & ODATFB_UNBUNCH)) {
+				if (v->HasFullLoadOrder()) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD);
+				if (v->HasUnbunchingOrder()) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_UNBUNCHING_ONLY_ONE_ALLOWED);
+				if (v->HasConditionalOrder()) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL);
+			}
 			break;
 		}
 
@@ -1304,12 +1313,10 @@ CommandCost CmdModifyOrder(DoCommandFlag flags, VehicleID veh, VehicleOrderID se
 			if (data == DA_UNBUNCH) {
 				/* Only one unbunching order is allowed in a vehicle's orders. If this order already has an unbunching action, no error is needed. */
 				if (v->HasUnbunchingOrder() && !(order->GetDepotActionType() & ODATFB_UNBUNCH)) return_cmd_error(STR_ERROR_UNBUNCHING_ONLY_ONE_ALLOWED);
-				for (Order *o : v->Orders()) {
-					/* We don't allow unbunching if the vehicle has a conditional order. */
-					if (o->IsType(OT_CONDITIONAL)) return_cmd_error(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL);
-					/* We don't allow unbunching if the vehicle has a full load order. */
-					if (o->IsType(OT_GOTO_STATION) && o->GetLoadType() & (OLFB_FULL_LOAD | OLF_FULL_LOAD_ANY)) return_cmd_error(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD);
-				}
+				/* We don't allow unbunching if the vehicle has a conditional order. */
+				if (v->HasConditionalOrder()) return_cmd_error(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL);
+				/* We don't allow unbunching if the vehicle has a full load order. */
+				if (v->HasFullLoadOrder()) return_cmd_error(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD);
 			}
 			break;
 
diff --git a/src/order_gui.cpp b/src/order_gui.cpp
index 8c8e16dfa9..02765ceece 100644
--- a/src/order_gui.cpp
+++ b/src/order_gui.cpp
@@ -399,16 +399,32 @@ static Order GetOrderCmdFromTile(const Vehicle *v, TileIndex tile)
 				(_settings_client.gui.new_nonstop && v->IsGroundVehicle()) ? ONSF_NO_STOP_AT_INTERMEDIATE_STATIONS : ONSF_STOP_EVERYWHERE);
 
 		if (_ctrl_pressed) {
-			/* Don't allow a new unbunching order if we already have one. */
-			if (v->HasUnbunchingOrder()) {
+			/* Check to see if we are allowed to make this an unbunching order. */
+			bool failed = false;
+			if (v->HasFullLoadOrder()) {
+				/* We don't allow unbunching if the vehicle has a full load order. */
+				ShowErrorMessage(STR_ERROR_CAN_T_INSERT_NEW_ORDER, STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD, WL_ERROR);
+				failed = true;
+			} else if (v->HasUnbunchingOrder()) {
+				/* Don't allow a new unbunching order if we already have one. */
 				ShowErrorMessage(STR_ERROR_CAN_T_INSERT_NEW_ORDER, STR_ERROR_UNBUNCHING_ONLY_ONE_ALLOWED, WL_ERROR);
-				/* Return an empty order to bail out. */
+				failed = true;
+			} else if (v->HasConditionalOrder()) {
+				/* We don't allow unbunching if the vehicle has a conditional order. */
+				ShowErrorMessage(STR_ERROR_CAN_T_INSERT_NEW_ORDER, STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL, WL_ERROR);
+				failed = true;
+			}
+
+			/* Return an empty order to bail out. */
+			if (failed) {
 				order.Free();
 				return order;
-			} else {
-				order.SetDepotActionType(ODATFB_UNBUNCH);
 			}
+
+			/* Now we are allowed to set the action type. */
+			order.SetDepotActionType(ODATFB_UNBUNCH);
 		}
+
 		return order;
 	}
 
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 9ca49be6ad..2a03d75301 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -2426,6 +2426,30 @@ void Vehicle::HandleLoading(bool mode)
 	this->IncrementImplicitOrderIndex();
 }
 
+/**
+ * Check if the current vehicle has a full load order.
+ * @return true Iff this vehicle has a full load order.
+ */
+bool Vehicle::HasFullLoadOrder() const
+{
+	for (Order *o : this->Orders()) {
+		if (o->IsType(OT_GOTO_STATION) && o->GetLoadType() & (OLFB_FULL_LOAD | OLF_FULL_LOAD_ANY)) return true;
+	}
+	return false;
+}
+
+/**
+ * Check if the current vehicle has a conditional order.
+ * @return true Iff this vehicle has a conditional order.
+ */
+bool Vehicle::HasConditionalOrder() const
+{
+	for (Order *o : this->Orders()) {
+		if (o->IsType(OT_CONDITIONAL)) return true;
+	}
+	return false;
+}
+
 /**
  * Check if the current vehicle has an unbunching order.
  * @return true Iff this vehicle has an unbunching order.
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index 073a356c79..947e6f86a0 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -819,6 +819,8 @@ public:
 
 	inline void SetServiceIntervalIsPercent(bool on) { SB(this->vehicle_flags, VF_SERVINT_IS_PERCENT, 1, on); }
 
+	bool HasFullLoadOrder() const;
+	bool HasConditionalOrder() const;
 	bool HasUnbunchingOrder() const;
 	void LeaveUnbunchingDepot();
 	bool IsWaitingForUnbunching() const;