diff --git a/tests/instance-id.cpp b/tests/instance-id.cpp
new file mode 100644
index 0000000..e26563f
--- /dev/null
+++ b/tests/instance-id.cpp
@@ -0,0 +1,196 @@
+#include "libpldm/instance-id.h"
+
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <filesystem>
+
+#include "libpldm/base.h"
+
+#include <gtest/gtest.h>
+
+static constexpr auto pldmMaxInstanceIds = 32;
+static const std::filesystem::path nonexistentDb = {"remove-this-file"};
+
+TEST(InstanceId, dbInstanceNullDb)
+{
+    ASSERT_FALSE(std::filesystem::exists(nonexistentDb));
+    EXPECT_EQ(::pldm_instance_db_init(nullptr, nonexistentDb.c_str()), -EINVAL);
+}
+
+TEST(InstanceId, dbInstanceNonNullDerefDb)
+{
+    struct pldm_instance_db* db = (struct pldm_instance_db*)8;
+
+    ASSERT_FALSE(std::filesystem::exists(nonexistentDb));
+    EXPECT_EQ(::pldm_instance_db_init(&db, nonexistentDb.c_str()), -EINVAL);
+}
+
+TEST(InstanceId, dbInstanceInvalidPath)
+{
+    struct pldm_instance_db* db = nullptr;
+
+    EXPECT_NE(::pldm_instance_db_init(&db, ""), 0);
+}
+
+class PldmInstanceDbTest : public ::testing::Test
+{
+  protected:
+    void SetUp() override
+    {
+        static const char dbTmpl[] = "db.XXXXXX";
+        char dbName[sizeof(dbTmpl)] = {};
+        int fd;
+
+        ::strncpy(dbName, dbTmpl, sizeof(dbName));
+        fd = ::mkstemp(dbName);
+        ASSERT_NE(fd, -1);
+
+        dbPath = std::filesystem::path(dbName);
+        std::filesystem::resize_file(
+            dbPath, (uintmax_t)(PLDM_MAX_TIDS)*pldmMaxInstanceIds);
+    }
+
+    void TearDown() override
+    {
+        std::filesystem::remove(dbPath);
+        ::close(fd);
+    }
+
+    std::filesystem::path dbPath;
+
+  private:
+    int fd;
+};
+
+TEST_F(PldmInstanceDbTest, dbInstance)
+{
+    struct pldm_instance_db* db = nullptr;
+
+    EXPECT_EQ(pldm_instance_db_init(&db, dbPath.c_str()), 0);
+    EXPECT_EQ(pldm_instance_db_destroy(db), 0);
+}
+
+TEST_F(PldmInstanceDbTest, allocFreeOne)
+{
+    struct pldm_instance_db* db = nullptr;
+    const pldm_tid_t tid = 1;
+    pldm_instance_id_t iid;
+
+    ASSERT_EQ(pldm_instance_db_init(&db, dbPath.c_str()), 0);
+    EXPECT_EQ(pldm_instance_id_alloc(db, tid, &iid), 0);
+    EXPECT_EQ(pldm_instance_id_free(db, tid, iid), 0);
+    ASSERT_EQ(pldm_instance_db_destroy(db), 0);
+}
+
+TEST_F(PldmInstanceDbTest, allocFreeTwoSerialSameTid)
+{
+    static constexpr pldm_tid_t tid = 1;
+
+    struct pldm_instance_db* db = nullptr;
+    pldm_instance_id_t first;
+    pldm_instance_id_t second;
+
+    ASSERT_EQ(pldm_instance_db_init(&db, dbPath.c_str()), 0);
+    EXPECT_EQ(pldm_instance_id_alloc(db, tid, &first), 0);
+    EXPECT_EQ(pldm_instance_id_free(db, tid, first), 0);
+    EXPECT_EQ(pldm_instance_id_alloc(db, tid, &second), 0);
+    EXPECT_EQ(pldm_instance_id_free(db, tid, second), 0);
+    EXPECT_NE(first, second);
+    ASSERT_EQ(pldm_instance_db_destroy(db), 0);
+}
+
+TEST_F(PldmInstanceDbTest, allocFreeTwoSerialDifferentTid)
+{
+    struct
+    {
+        pldm_tid_t tid;
+        pldm_instance_id_t iid;
+    } instances[] = {
+        {1, 0},
+        {2, 0},
+    };
+
+    struct pldm_instance_db* db = nullptr;
+
+    ASSERT_EQ(pldm_instance_db_init(&db, dbPath.c_str()), 0);
+
+    EXPECT_EQ(pldm_instance_id_alloc(db, instances[0].tid, &instances[0].iid),
+              0);
+    EXPECT_EQ(pldm_instance_id_alloc(db, instances[1].tid, &instances[1].iid),
+              0);
+
+    EXPECT_EQ(instances[0].iid, instances[1].iid);
+
+    EXPECT_EQ(pldm_instance_id_free(db, instances[1].tid, instances[1].iid), 0);
+    EXPECT_EQ(pldm_instance_id_free(db, instances[0].tid, instances[0].iid), 0);
+
+    ASSERT_EQ(pldm_instance_db_destroy(db), 0);
+}
+
+TEST_F(PldmInstanceDbTest, allocFreeTwoConcurrentSameTid)
+{
+    static constexpr pldm_tid_t tid = 1;
+
+    struct
+    {
+        struct pldm_instance_db* db;
+        pldm_instance_id_t iid;
+    } connections[] = {
+        {nullptr, 0},
+        {nullptr, 0},
+    };
+
+    ASSERT_EQ(pldm_instance_db_init(&connections[0].db, dbPath.c_str()), 0);
+    EXPECT_EQ(
+        pldm_instance_id_alloc(connections[0].db, tid, &connections[0].iid), 0);
+
+    ASSERT_EQ(pldm_instance_db_init(&connections[1].db, dbPath.c_str()), 0);
+    EXPECT_EQ(
+        pldm_instance_id_alloc(connections[1].db, tid, &connections[1].iid), 0);
+
+    EXPECT_NE(connections[0].iid, connections[1].iid);
+
+    EXPECT_EQ(pldm_instance_id_free(connections[1].db, tid, connections[1].iid),
+              0);
+    ASSERT_EQ(pldm_instance_db_destroy(connections[1].db), 0);
+
+    EXPECT_EQ(pldm_instance_id_free(connections[0].db, tid, connections[0].iid),
+              0);
+    ASSERT_EQ(pldm_instance_db_destroy(connections[0].db), 0);
+}
+
+TEST_F(PldmInstanceDbTest, allocFreeTwoConcurrentDifferentTid)
+{
+    struct
+    {
+        struct pldm_instance_db* db;
+        pldm_tid_t tid;
+        pldm_instance_id_t iid;
+    } connections[] = {
+        {nullptr, 1, 0},
+        {nullptr, 2, 0},
+    };
+
+    ASSERT_EQ(pldm_instance_db_init(&connections[0].db, dbPath.c_str()), 0);
+    EXPECT_EQ(pldm_instance_id_alloc(connections[0].db, connections[0].tid,
+                                     &connections[0].iid),
+              0);
+
+    ASSERT_EQ(pldm_instance_db_init(&connections[1].db, dbPath.c_str()), 0);
+    EXPECT_EQ(pldm_instance_id_alloc(connections[1].db, connections[1].tid,
+                                     &connections[1].iid),
+              0);
+
+    EXPECT_EQ(connections[0].iid, connections[1].iid);
+
+    EXPECT_EQ(pldm_instance_id_free(connections[1].db, connections[1].tid,
+                                    connections[1].iid),
+              0);
+    ASSERT_EQ(pldm_instance_db_destroy(connections[1].db), 0);
+
+    EXPECT_EQ(pldm_instance_id_free(connections[0].db, connections[0].tid,
+                                    connections[0].iid),
+              0);
+    ASSERT_EQ(pldm_instance_db_destroy(connections[0].db), 0);
+}
diff --git a/tests/meson.build b/tests/meson.build
index aba89bc..c41d8d2 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -14,6 +14,7 @@
 
 
 tests = [
+  'instance-id',
   'libpldm_base_test',
   'libpldm_platform_test',
   'libpldm_bios_test',