diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index 5f0fe41490..25b9162ad0 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -469,7 +469,7 @@ CommandCost CmdInsertOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 	Order new_order(p2);
 
 	Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -560,8 +560,6 @@ CommandCost CmdInsertOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 						default: return CMD_ERROR;
 					}
 				}
-			} else {
-				if (!IsCompanyBuildableVehicleType(v)) return CMD_ERROR;
 			}
 
 			if (new_order.GetNonStopType() != ONSF_STOP_EVERYWHERE && v->type != VEH_TRAIN && v->type != VEH_ROAD) return CMD_ERROR;
@@ -748,7 +746,7 @@ CommandCost CmdDeleteOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 
 	Vehicle *v = Vehicle::GetIfValid(veh_id);
 
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -817,7 +815,7 @@ CommandCost CmdSkipToOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 
 	Vehicle *v = Vehicle::GetIfValid(veh_id);
 
-	if (v == NULL || sel_ord == v->cur_order_index || sel_ord >= v->GetNumOrders() || v->GetNumOrders() < 2) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle() || sel_ord == v->cur_order_index || sel_ord >= v->GetNumOrders() || v->GetNumOrders() < 2) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -857,7 +855,7 @@ CommandCost CmdMoveOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	VehicleOrderID target_order = GB(p2, 16, 16);
 
 	Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -940,7 +938,7 @@ CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 	if (mof >= MOF_END) return CMD_ERROR;
 
 	Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -1166,7 +1164,7 @@ CommandCost CmdCloneOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	VehicleID veh_dst = GB(p1,  0, 16);
 
 	Vehicle *dst = Vehicle::GetIfValid(veh_dst);
-	if (dst == NULL) return CMD_ERROR;
+	if (dst == NULL || !dst->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(dst->owner);
 	if (ret.Failed()) return ret;
@@ -1176,7 +1174,7 @@ CommandCost CmdCloneOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 			Vehicle *src = Vehicle::GetIfValid(veh_src);
 
 			/* Sanity checks */
-			if (src == NULL || dst->type != src->type || dst == src) return CMD_ERROR;
+			if (src == NULL || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
 			CommandCost ret = CheckOwnership(src->owner);
 			if (ret.Failed()) return ret;
@@ -1218,7 +1216,7 @@ CommandCost CmdCloneOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 			Vehicle *src = Vehicle::GetIfValid(veh_src);
 
 			/* Sanity checks */
-			if (src == NULL || dst->type != src->type || dst == src) return CMD_ERROR;
+			if (src == NULL || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
 			CommandCost ret = CheckOwnership(src->owner);
 			if (ret.Failed()) return ret;
@@ -1294,8 +1292,10 @@ CommandCost CmdOrderRefit(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	CargoID cargo = GB(p2, 0, 8);
 	byte subtype  = GB(p2, 8, 8);
 
+	if (cargo >= NUM_CARGO) return CMD_ERROR;
+
 	const Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -1450,7 +1450,7 @@ CommandCost CmdRestoreOrderIndex(TileIndex tile, DoCommandFlag flags, uint32 p1,
 
 	Vehicle *v = Vehicle::GetIfValid(p1);
 	/* Check the vehicle type and ownership, and if the service interval and order are in range */
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
diff --git a/src/vehicle_cmd.cpp b/src/vehicle_cmd.cpp
index 6a72fbbffa..c621ed271b 100644
--- a/src/vehicle_cmd.cpp
+++ b/src/vehicle_cmd.cpp
@@ -410,7 +410,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 	uint32 build_argument = 2;
 
 	Vehicle *v = Vehicle::GetIfValid(p1);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 	Vehicle *v_front = v;
 	Vehicle *w = NULL;
 	Vehicle *w_front = NULL;
@@ -629,7 +629,7 @@ CommandCost SendAllVehiclesToDepot(VehicleType type, DoCommandFlag flags, bool s
 CommandCost CmdRenameVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 {
 	Vehicle *v = Vehicle::GetIfValid(p1);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -663,7 +663,7 @@ CommandCost CmdRenameVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 CommandCost CmdChangeServiceInt(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 {
 	Vehicle *v = Vehicle::GetIfValid(p1);
-	if (v == NULL) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;