diff --git a/src/array.h b/src/array.h
index 05f26bd..45e83aa 100644
--- a/src/array.h
+++ b/src/array.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef LIBPLDM_SRC_ARRAY_H
 #define LIBPLDM_SRC_ARRAY_H
 
diff --git a/src/base.c b/src/base.c
index 908621b..4322ef2 100644
--- a/src/base.c
+++ b/src/base.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "base.h"
 #include "pldm_types.h"
 #include <endian.h>
diff --git a/src/bios.c b/src/bios.c
index 45dc897..83c6dc9 100644
--- a/src/bios.c
+++ b/src/bios.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "bios.h"
 #include "base.h"
 #include "utils.h"
diff --git a/src/bios_table.c b/src/bios_table.c
index db1a6be..228bff4 100644
--- a/src/bios_table.c
+++ b/src/bios_table.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "array.h"
 #include "bios_table.h"
 #include "base.h"
diff --git a/src/firmware_update.c b/src/firmware_update.c
index 3cab7d0..22b4387 100644
--- a/src/firmware_update.c
+++ b/src/firmware_update.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "firmware_update.h"
 #include "utils.h"
 #include <endian.h>
diff --git a/src/fru.c b/src/fru.c
index b0cb864..024a34f 100644
--- a/src/fru.c
+++ b/src/fru.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include <assert.h>
 #include <endian.h>
 #include <stdbool.h>
diff --git a/src/mctp-defines.h b/src/mctp-defines.h
index 912d47c..620115f 100644
--- a/src/mctp-defines.h
+++ b/src/mctp-defines.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef MCTP_DEFINES_H
 #define MCTP_DEFINES_H
 
diff --git a/src/msgbuf.h b/src/msgbuf.h
index 128b4be..4c0e61c 100644
--- a/src/msgbuf.h
+++ b/src/msgbuf.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef PLDM_MSGBUF_H
 #define PLDM_MSGBUF_H
 
diff --git a/src/msgbuf/platform.h b/src/msgbuf/platform.h
index bc296b8..3fbe077 100644
--- a/src/msgbuf/platform.h
+++ b/src/msgbuf/platform.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef PLDM_MSGBUF_PLATFORM_H
 #define PLDM_MSGBUF_PLATFORM_H
 
diff --git a/src/oem/ibm/file_io.c b/src/oem/ibm/file_io.c
index 05b81c6..ba0111a 100644
--- a/src/oem/ibm/file_io.c
+++ b/src/oem/ibm/file_io.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "libpldm/file_io.h"
 #include "base.h"
 #include <endian.h>
diff --git a/src/oem/ibm/host.c b/src/oem/ibm/host.c
index 04ba5f3..c94ee49 100644
--- a/src/oem/ibm/host.c
+++ b/src/oem/ibm/host.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "base.h"
 #include <endian.h>
 #include <stdint.h>
diff --git a/src/oem/ibm/platform.c b/src/oem/ibm/platform.c
index 462f378..3a8b2f8 100644
--- a/src/oem/ibm/platform.c
+++ b/src/oem/ibm/platform.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "libpldm/platform.h"
 #include "libpldm/platform_oem_ibm.h"
 #include <string.h>
diff --git a/src/pdr.c b/src/pdr.c
index 72cab7e..ee699c7 100644
--- a/src/pdr.c
+++ b/src/pdr.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "pdr.h"
 #include "platform.h"
 #include <assert.h>
diff --git a/src/platform.c b/src/platform.c
index 8619772..a24cd30 100644
--- a/src/platform.c
+++ b/src/platform.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "msgbuf/platform.h"
 #include "base.h"
 #include "msgbuf.h"
diff --git a/src/requester/instance-id.c b/src/requester/instance-id.c
index a079f7b..108e451 100644
--- a/src/requester/instance-id.c
+++ b/src/requester/instance-id.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 // NOLINTNEXTLINE(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp)
 #define _GNU_SOURCE
 #include "libpldm/instance-id.h"
diff --git a/src/requester/pldm.c b/src/requester/pldm.c
index 30687b3..9e6801a 100644
--- a/src/requester/pldm.c
+++ b/src/requester/pldm.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "libpldm/requester/pldm.h"
 #include "base.h"
 #include "libpldm/transport.h"
diff --git a/src/responder.c b/src/responder.c
index 5112f7b..9940fa0 100644
--- a/src/responder.c
+++ b/src/responder.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "responder.h"
 
 #include <libpldm/base.h>
diff --git a/src/responder.h b/src/responder.h
index 37df828..1295cda 100644
--- a/src/responder.h
+++ b/src/responder.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef LIBPLDM_SRC_RESPONDER_H
 #define LIBPLDM_SRC_RESPONDER_H
 
diff --git a/src/transport/af-mctp.c b/src/transport/af-mctp.c
index 34454b3..bf024b8 100644
--- a/src/transport/af-mctp.c
+++ b/src/transport/af-mctp.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "mctp-defines.h"
 #include "base.h"
 #include "container-of.h"
diff --git a/src/transport/container-of.h b/src/transport/container-of.h
index facefe5..4c6ce1b 100644
--- a/src/transport/container-of.h
+++ b/src/transport/container-of.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef CONTAINER_OF_H
 #define CONTAINER_OF_H
 
diff --git a/src/transport/mctp-demux.c b/src/transport/mctp-demux.c
index 8b35c0a..a874cef 100644
--- a/src/transport/mctp-demux.c
+++ b/src/transport/mctp-demux.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "mctp-defines.h"
 #include "base.h"
 #include "container-of.h"
diff --git a/src/transport/socket.c b/src/transport/socket.c
index 8c5dd01..4498356 100644
--- a/src/transport/socket.c
+++ b/src/transport/socket.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "socket.h"
 
 #include <errno.h>
diff --git a/src/transport/socket.h b/src/transport/socket.h
index 17751ca..09c697a 100644
--- a/src/transport/socket.h
+++ b/src/transport/socket.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef LIBPLDM_SRC_TRANSPORT_SOCKET_H
 #define LIBPLDM_SRC_TRANSPORT_SOCKET_H
 
diff --git a/src/transport/test.c b/src/transport/test.c
index 730d8e6..2a929cc 100644
--- a/src/transport/test.c
+++ b/src/transport/test.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 /* NOLINTNEXTLINE(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp) */
 #define _GNU_SOURCE
 #include "array.h"
diff --git a/src/transport/transport.c b/src/transport/transport.c
index 12a26aa..bc01000 100644
--- a/src/transport/transport.c
+++ b/src/transport/transport.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "libpldm/transport.h"
 #include "libpldm/base.h"
 #include "libpldm/requester/pldm.h"
diff --git a/src/transport/transport.h b/src/transport/transport.h
index f052785..81d7b61 100644
--- a/src/transport/transport.h
+++ b/src/transport/transport.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #ifndef LIBPLDM_SRC_TRANSPORT_TRANSPORT_H
 #define LIBPLDM_SRC_TRANSPORT_TRANSPORT_H
 
diff --git a/src/utils.c b/src/utils.c
index f6a2b7b..0e24da5 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "utils.h"
 #include "base.h"
 #include <limits.h>