diff --git a/include/zephyr/usb/usbd.h b/include/zephyr/usb/usbd.h
index c060411..12ce411 100644
--- a/include/zephyr/usb/usbd.h
+++ b/include/zephyr/usb/usbd.h
@@ -50,9 +50,14 @@
  */
 #define USB_STRING_DESCRIPTOR_LENGTH(s)	(sizeof(s) * 2)
 
-#define USBD_DESC_MANUFACTURER_IDX		1
-#define USBD_DESC_PRODUCT_IDX			2
-#define USBD_DESC_SERIAL_NUMBER_IDX		3
+/* Used internally to keep descriptors in order */
+enum usbd_desc_usage_type {
+	USBD_DUT_STRING_LANG,
+	USBD_DUT_STRING_MANUFACTURER,
+	USBD_DUT_STRING_PRODUCT,
+	USBD_DUT_STRING_SERIAL_NUMBER,
+	USBD_DUT_STRING_INTERFACE,
+};
 
 /**
  * Descriptor node
@@ -65,6 +70,8 @@
 	sys_dnode_t node;
 	/** Descriptor index, required for string descriptors */
 	unsigned int idx : 8;
+	/** Descriptor usage type (not bDescriptorType) */
+	unsigned int utype : 8;
 	/** If not set, string descriptor must be converted to UTF16LE */
 	unsigned int utf16le : 1;
 	/** If not set, device stack obtains SN using the hwinfo API */
@@ -312,7 +319,19 @@
 		.desc = &cfg_desc_##name,				\
 	}
 
-
+/**
+ * @brief Create a string descriptor node and language string descriptor
+ *
+ * This macro defines a descriptor node and a string descriptor that,
+ * when added to the device context, is automatically used as the language
+ * string descriptor zero. Both descriptor node and descriptor are defined with
+ * static-storage-class specifier. Default and currently only supported
+ * language ID is 0x0409 English (United States).
+ * If string descriptors are used, it is necessary to add this descriptor
+ * as the first one to the USB device context.
+ *
+ * @param name Language string descriptor node identifier.
+ */
 #define USBD_DESC_LANG_DEFINE(name)					\
 	static struct usb_string_descriptor				\
 	string_desc_##name = {						\
@@ -322,10 +341,11 @@
 	};								\
 	static struct usbd_desc_node name = {				\
 		.idx = 0,						\
+		.utype = USBD_DUT_STRING_LANG,				\
 		.desc = &string_desc_##name,				\
 	}
 
-#define USBD_DESC_STRING_DEFINE(d_name, d_string, d_idx)		\
+#define USBD_DESC_STRING_DEFINE(d_name, d_string, d_utype)		\
 	struct usb_string_descriptor_##d_name {				\
 		uint8_t bLength;					\
 		uint8_t bDescriptorType;				\
@@ -337,20 +357,53 @@
 		.bDescriptorType = USB_DESC_STRING,			\
 		.bString = d_string,					\
 	};								\
-	BUILD_ASSERT(d_idx != 0, "Index 0 is not allowed");		\
 	static struct usbd_desc_node d_name = {				\
-		.idx = d_idx,						\
+		.utype = d_utype,					\
 		.desc = &string_desc_##d_name,				\
 	}
 
+/**
+ * @brief Create a string descriptor node and manufacturer string descriptor
+ *
+ * This macro defines a descriptor node and a string descriptor that,
+ * when added to the device context, is automatically used as the manufacturer
+ * string descriptor. Both descriptor node and descriptor are defined with
+ * static-storage-class specifier.
+ *
+ * @param d_name   String descriptor node identifier.
+ * @param d_string ASCII7 encoded manufacturer string literal
+ */
 #define USBD_DESC_MANUFACTURER_DEFINE(d_name, d_string)			\
-	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DESC_MANUFACTURER_IDX)
+	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DUT_STRING_MANUFACTURER)
 
+/**
+ * @brief Create a string descriptor node and product string descriptor
+ *
+ * This macro defines a descriptor node and a string descriptor that,
+ * when added to the device context, is automatically used as the product
+ * string descriptor. Both descriptor node and descriptor are defined with
+ * static-storage-class specifier.
+ *
+ * @param d_name   String descriptor node identifier.
+ * @param d_string ASCII7 encoded product string literal
+ */
 #define USBD_DESC_PRODUCT_DEFINE(d_name, d_string)			\
-	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DESC_PRODUCT_IDX)
+	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DUT_STRING_PRODUCT)
 
+/**
+ * @brief Create a string descriptor node and serial number string descriptor
+ *
+ * This macro defines a descriptor node and a string descriptor that,
+ * when added to the device context, is automatically used as the serial number
+ * string descriptor. The string literal parameter is used as a placeholder,
+ * the unique number is obtained from hwinfo. Both descriptor node and descriptor
+ * are defined with static-storage-class specifier.
+ *
+ * @param d_name   String descriptor node identifier.
+ * @param d_string ASCII7 encoded serial number string literal placeholder
+ */
 #define USBD_DESC_SERIAL_NUMBER_DEFINE(d_name, d_string)		\
-	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DESC_SERIAL_NUMBER_IDX)
+	USBD_DESC_STRING_DEFINE(d_name, d_string, USBD_DUT_STRING_SERIAL_NUMBER)
 
 #define USBD_DEFINE_CLASS(class_name, class_api, class_data)		\
 	static STRUCT_SECTION_ITERABLE(usbd_class_node, class_name) = {	\
diff --git a/subsys/usb/device_next/class/usbd_cdc_ecm.c b/subsys/usb/device_next/class/usbd_cdc_ecm.c
index 00525bc..6f7200c 100644
--- a/subsys/usb/device_next/class/usbd_cdc_ecm.c
+++ b/subsys/usb/device_next/class/usbd_cdc_ecm.c
@@ -24,12 +24,6 @@
 #define CDC_ECM_EP_MPS_INT		16
 #define CDC_ECM_EP_INTERVAL_INT		0x0A
 
-/*
- * REVISE: We can change usbd_add_descriptor() so that hardcoded
- * indexes are not necessary.
- */
-#define CDC_ECM_IMAC_BASE		4
-
 enum {
 	CDC_ECM_IFACE_UP,
 	CDC_ECM_CLASS_ENABLED,
@@ -416,12 +410,24 @@
 	LOG_DBG("CDC ECM class initialized");
 
 	if (usbd_add_descriptor(c_nd->data->uds_ctx, data->mac_desc_nd)) {
-		LOG_ERR("Failed to add iMACAddress");
+		LOG_ERR("Failed to add iMACAddress string descriptor");
+	} else {
+		desc->if0_ecm.iMACAddress = data->mac_desc_nd->idx;
 	}
 
 	return 0;
 }
 
+static void usbd_cdc_ecm_shutdown(struct usbd_class_node *const c_nd)
+{
+	struct usbd_cdc_ecm_desc *desc = c_nd->data->desc;
+	const struct device *dev = c_nd->data->priv;
+	struct cdc_ecm_eth_data *const data = dev->data;
+
+	desc->if0_ecm.iMACAddress = 0;
+	sys_dlist_remove(&data->mac_desc_nd->node);
+}
+
 static int cdc_ecm_send(const struct device *dev, struct net_pkt *const pkt)
 {
 	struct cdc_ecm_eth_data *const data = dev->data;
@@ -573,6 +579,7 @@
 	.resumed = usbd_cdc_ecm_resumed,
 	.control_to_dev = usbd_cdc_ecm_ctd,
 	.init = usbd_cdc_ecm_init,
+	.shutdown = usbd_cdc_ecm_shutdown,
 };
 
 static const struct ethernet_api cdc_ecm_eth_api = {
@@ -629,7 +636,7 @@
 		.bFunctionLength = sizeof(struct cdc_ecm_descriptor),		\
 		.bDescriptorType = USB_DESC_CS_INTERFACE,			\
 		.bDescriptorSubtype = ETHERNET_FUNC_DESC,			\
-		.iMACAddress = CDC_ECM_IMAC_BASE + n,				\
+		.iMACAddress = 0,						\
 		.bmEthernetStatistics = sys_cpu_to_le32(0),			\
 		.wMaxSegmentSize = sys_cpu_to_le16(NET_ETH_MAX_FRAME_SIZE),	\
 		.wNumberMCFilters = sys_cpu_to_le16(0),				\
@@ -697,7 +704,7 @@
 	CDC_ECM_DEFINE_DESCRIPTOR(n);						\
 	USBD_DESC_STRING_DEFINE(mac_desc_nd_##n,				\
 				DT_INST_PROP(n, remote_mac_address),		\
-				CDC_ECM_IMAC_BASE + n);				\
+				USBD_DUT_STRING_INTERFACE);			\
 										\
 	static struct usbd_class_data usbd_cdc_ecm_data_##n;			\
 										\
diff --git a/subsys/usb/device_next/usbd_desc.c b/subsys/usb/device_next/usbd_desc.c
index 2f20614..2e8cb1c 100644
--- a/subsys/usb/device_next/usbd_desc.c
+++ b/subsys/usb/device_next/usbd_desc.c
@@ -104,6 +104,73 @@
 	return 0;
 }
 
+static inline bool desc_type_equal(const struct usbd_desc_node *const a,
+				   const struct usbd_desc_node *const b)
+{
+	const struct usb_desc_header *const head_a = a->desc;
+	const struct usb_desc_header *const head_b = b->desc;
+
+	return head_a->bDescriptorType == head_b->bDescriptorType;
+}
+
+/*
+ * Add descriptor node to the descriptor list in ascending order by index
+ * and sorted by bDescriptorType. For the string descriptors, the function
+ * does not care about index zero for the language string descriptor,
+ * so if it is not added first, the device will be non-compliant.
+ */
+static int desc_add_and_update_idx(struct usbd_contex *const uds_ctx,
+				   struct usbd_desc_node *const new_nd)
+{
+	struct usbd_desc_node *tmp_nd;
+
+	SYS_DLIST_FOR_EACH_CONTAINER(&uds_ctx->descriptors, tmp_nd, node) {
+		struct usbd_desc_node *next_nd;
+
+		if (!desc_type_equal(tmp_nd, new_nd)) {
+			continue;
+		}
+
+		next_nd = SYS_DLIST_PEEK_NEXT_CONTAINER(&uds_ctx->descriptors,
+							tmp_nd,
+							node);
+
+		if (next_nd == NULL) {
+			/* Last node of the same bDescriptorType or tail */
+			new_nd->idx = tmp_nd->idx + 1;
+			sys_dlist_append(&uds_ctx->descriptors, &new_nd->node);
+			LOG_DBG("Add %u behind %u", new_nd->idx, tmp_nd->idx);
+
+			return 0;
+		}
+
+		if (!desc_type_equal(next_nd, new_nd)) {
+			/* Last node of the same bDescriptorType */
+			new_nd->idx = tmp_nd->idx + 1;
+			sys_dlist_insert(&next_nd->node, &new_nd->node);
+			LOG_DBG("Add %u before %u", new_nd->idx, next_nd->idx);
+
+			return 0;
+		}
+
+		if (tmp_nd->idx != (next_nd->idx - 1)) {
+			/* Add between nodes of the same bDescriptorType */
+			new_nd->idx = tmp_nd->idx + 1;
+			sys_dlist_insert(&next_nd->node, &new_nd->node);
+			LOG_DBG("Add %u between %u and %u",
+				tmp_nd->idx, next_nd->idx, new_nd->idx);
+			return 0;
+		}
+	}
+
+	/* If there are none of same bDescriptorType, node idx is set to 0. */
+	new_nd->idx = 0;
+	sys_dlist_append(&uds_ctx->descriptors, &new_nd->node);
+	LOG_DBG("Added first descriptor node (usage type %u)", new_nd->utype);
+
+	return 0;
+}
+
 void *usbd_get_descriptor(struct usbd_contex *const uds_ctx,
 			  const uint8_t type, const uint8_t idx)
 {
@@ -136,12 +203,17 @@
 int usbd_add_descriptor(struct usbd_contex *const uds_ctx,
 			struct usbd_desc_node *const desc_nd)
 {
+	struct usb_device_descriptor *dev_desc = uds_ctx->desc;
 	struct usb_desc_header *head;
-	uint8_t type;
 	int ret = 0;
 
 	usbd_device_lock(uds_ctx);
 
+	if (dev_desc == NULL || usbd_is_initialized(uds_ctx)) {
+		ret = -EPERM;
+		goto add_descriptor_error;
+	}
+
 	/* Check if descriptor list is initialized */
 	if (!sys_dnode_is_linked(&uds_ctx->descriptors)) {
 		LOG_DBG("Initialize descriptors list");
@@ -149,28 +221,28 @@
 	}
 
 	head = desc_nd->desc;
-	type = head->bDescriptorType;
 	if (sys_dnode_is_linked(&desc_nd->node)) {
 		ret = -EALREADY;
 		goto add_descriptor_error;
 	}
 
-	if (type == USB_DESC_STRING) {
-		struct usb_device_descriptor *dev_desc = uds_ctx->desc;
+	ret = desc_add_and_update_idx(uds_ctx, desc_nd);
+	if (ret) {
+		ret = -EINVAL;
+		goto add_descriptor_error;
+	}
 
-		if (dev_desc == NULL) {
-			ret = -EPERM;
-			goto add_descriptor_error;
-		}
-
-		switch (desc_nd->idx) {
-		case USBD_DESC_MANUFACTURER_IDX:
+	if (head->bDescriptorType == USB_DESC_STRING) {
+		switch (desc_nd->utype) {
+		case USBD_DUT_STRING_LANG:
+			break;
+		case USBD_DUT_STRING_MANUFACTURER:
 			dev_desc->iManufacturer = desc_nd->idx;
 			break;
-		case USBD_DESC_PRODUCT_IDX:
+		case USBD_DUT_STRING_PRODUCT:
 			dev_desc->iProduct = desc_nd->idx;
 			break;
-		case USBD_DESC_SERIAL_NUMBER_IDX:
+		case USBD_DUT_STRING_SERIAL_NUMBER:
 			if (!desc_nd->custom_sn) {
 				ret = usbd_get_sn_from_hwid(desc_nd);
 				desc_nd->utf16le = false;
@@ -187,8 +259,6 @@
 		}
 	}
 
-	sys_dlist_append(&uds_ctx->descriptors, &desc_nd->node);
-
 add_descriptor_error:
 	usbd_device_unlock(uds_ctx);
 	return ret;