diff --git a/doc/releases/release-notes-2.3.rst b/doc/releases/release-notes-2.3.rst
index 6b1212e81a1..1ff7954b492 100644
--- a/doc/releases/release-notes-2.3.rst
+++ b/doc/releases/release-notes-2.3.rst
@@ -21,6 +21,19 @@ No security vulnerabilities received.
 API Changes
 ***********
 
+* HWINFO
+
+  * The identifier data structure for hwinfo drivers is clarified.  Drivers are
+    responsible for ensuring that the identifier data structure is a sequence
+    of bytes. The returned ID value is not supposed to be interpreted based on
+    vendor-specific assumptions of byte order and should express the identifier
+    as a raw byte sequence.
+    The changes have an impact on users that use the hwinfo API to identify
+    their devices.
+    The sam0 driver byte swaps each 32 bit word of the 128 bit identifier to
+    big endian.
+    The nordic driver byte swaps the entire 64 bit word to big endian.
+
 Deprecated in this release
 ==========================
 
diff --git a/drivers/hwinfo/hwinfo_nrf.c b/drivers/hwinfo/hwinfo_nrf.c
index 6c2822d8913..efed51dd0fb 100644
--- a/drivers/hwinfo/hwinfo_nrf.c
+++ b/drivers/hwinfo/hwinfo_nrf.c
@@ -8,6 +8,7 @@
 #include <drivers/hwinfo.h>
 #include <string.h>
 #include <hal/nrf_ficr.h>
+#include <sys/byteorder.h>
 
 struct nrf_uid {
 	u32_t id[2];
@@ -17,8 +18,8 @@ ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct nrf_uid dev_id;
 
-	dev_id.id[0] = nrf_ficr_deviceid_get(NRF_FICR, 0);
-	dev_id.id[1] = nrf_ficr_deviceid_get(NRF_FICR, 1);
+	dev_id.id[0] = sys_cpu_to_be32(nrf_ficr_deviceid_get(NRF_FICR, 1));
+	dev_id.id[1] = sys_cpu_to_be32(nrf_ficr_deviceid_get(NRF_FICR, 0));
 
 	if (length > sizeof(dev_id.id)) {
 		length = sizeof(dev_id.id);
diff --git a/drivers/hwinfo/hwinfo_sam0.c b/drivers/hwinfo/hwinfo_sam0.c
index 309989ad241..308dd560a9d 100644
--- a/drivers/hwinfo/hwinfo_sam0.c
+++ b/drivers/hwinfo/hwinfo_sam0.c
@@ -9,6 +9,7 @@
 #include <soc.h>
 #include <drivers/hwinfo.h>
 #include <string.h>
+#include <sys/byteorder.h>
 
 struct sam0_uid {
 	u32_t id[4];
@@ -18,10 +19,14 @@ ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct sam0_uid dev_id;
 
-	dev_id.id[0] = *(const u32_t *) DT_INST_REG_ADDR_BY_IDX(0, 0);
-	dev_id.id[1] = *(const u32_t *) DT_INST_REG_ADDR_BY_IDX(0, 1);
-	dev_id.id[2] = *(const u32_t *) DT_INST_REG_ADDR_BY_IDX(0, 2);
-	dev_id.id[3] = *(const u32_t *) DT_INST_REG_ADDR_BY_IDX(0, 3);
+	dev_id.id[0] = sys_cpu_to_be32(*(const u32_t *)
+				       DT_INST_REG_ADDR_BY_IDX(0, 0));
+	dev_id.id[1] = sys_cpu_to_be32(*(const u32_t *)
+				       DT_INST_REG_ADDR_BY_IDX(0, 1));
+	dev_id.id[2] = sys_cpu_to_be32(*(const u32_t *)
+				       DT_INST_REG_ADDR_BY_IDX(0, 2));
+	dev_id.id[3] = sys_cpu_to_be32(*(const u32_t *)
+				       DT_INST_REG_ADDR_BY_IDX(0, 3));
 
 	if (length > sizeof(dev_id.id)) {
 		length = sizeof(dev_id.id);
diff --git a/include/drivers/hwinfo.h b/include/drivers/hwinfo.h
index baf1bf17e1e..d9dec16abb3 100644
--- a/include/drivers/hwinfo.h
+++ b/include/drivers/hwinfo.h
@@ -37,6 +37,12 @@ extern "C" {
  * If the device ID is smaller then length, the rest of the buffer is left unchanged.
  * The ID depends on the hardware and is not guaranteed unique.
  *
+ * Drivers are responsible for ensuring that the ID data structure is a
+ * sequence of bytes.  The returned ID value is not supposed to be interpreted
+ * based on vendor-specific assumptions of byte order. It should express the
+ * identifier as a raw byte sequence, doing any endian conversion necessary so
+ * that a hex representation of the bytes produces the intended serial number.
+ *
  * @param buffer  Buffer to write the ID to.
  * @param length  Max length of the buffer.
  *