diff --git a/src/core/dbus.c b/src/core/dbus.c
index 659965e4e6..5e5c3ccf1b 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -817,6 +817,68 @@ static int bus_setup_api(Manager *m, sd_bus *bus) {
         return 0;
 }
 
+static int api_bus_instance_id_reply(sd_bus_message *reply, void *userdata, sd_bus_error *reterr_error) {
+        Manager *m = ASSERT_PTR(userdata);
+        const sd_bus_error *e;
+        sd_bus *bus;
+        const char *id;
+        int r;
+
+        assert(reply);
+        assert_se(bus = sd_bus_message_get_bus(reply));
+
+        /* Whatever the outcome, we get only one shot at coldplugging the saved subscription state onto
+         * this connection: consume it. */
+        _cleanup_strv_free_ char **subscribed_as_strv = TAKE_PTR(m->subscribed_as_strv);
+        sd_id128_t deserialized_bus_id = m->deserialized_bus_id;
+        m->deserialized_bus_id = SD_ID128_NULL;
+
+        e = sd_bus_message_get_error(reply);
+        if (e) {
+                r = sd_bus_error_get_errno(e);
+                log_full_errno(subscribed_as_strv ? LOG_WARNING : LOG_DEBUG, r,
+                               "Failed to query API bus instance ID%s: %s",
+                               subscribed_as_strv ? ", not deserializing subscriptions" : ", ignoring",
+                               bus_error_message(e, r));
+                goto setup_api;
+        }
+
+        r = sd_bus_message_read_basic(reply, 's', &id);
+        if (r < 0) {
+                log_full_errno(subscribed_as_strv ? LOG_WARNING : LOG_DEBUG, r,
+                               "Failed to read API bus instance ID%s: %m",
+                               subscribed_as_strv ? ", not deserializing subscriptions" : ", ignoring");
+                goto setup_api;
+        }
+
+        r = sd_id128_from_string(id, &m->bus_id);
+        if (r < 0) {
+                log_full_errno(subscribed_as_strv ? LOG_WARNING : LOG_DEBUG, r,
+                               "API bus instance ID not in expected format%s: %m",
+                               subscribed_as_strv ? ", not deserializing subscriptions" : ", ignoring");
+                goto setup_api;
+        }
+
+        /* Coldplug the subscriptions deserialized from a previous reload/reexec (or saved when the
+         * previous connection was torn down), but only onto the same bus instance they were recorded on.
+         * If no instance ID was recorded, retain the historical behavior and coldplug without comparison. */
+        if (sd_id128_is_null(deserialized_bus_id) || sd_id128_equal(m->bus_id, deserialized_bus_id))
+                (void) bus_track_coldplug(bus, &m->subscribed, subscribed_as_strv);
+
+setup_api:
+        r = bus_setup_api(m, bus);
+        if (r < 0) {
+                log_error_errno(r, "Failed to set up API bus: %m");
+
+                if (m->system_bus == bus)
+                        bus_done_system(m);
+                if (m->api_bus == bus)
+                        bus_done_api(m);
+        }
+
+        return 0;
+}
+
 int bus_init_api(Manager *m) {
         _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
         int r;
@@ -846,17 +908,40 @@ int bus_init_api(Manager *m) {
                         return r;
         }
 
-        r = bus_setup_api(m, bus);
-        if (r < 0)
-                return log_error_errno(r, "Failed to set up API bus: %m");
+        /* Query the bus instance ID asynchronously, and let the reply handler decide whether the
+         * subscription state deserialized from a previous reload/reexec (or saved when the previous
+         * connection was torn down) may be coldplugged onto this connection. Set up the API only after the
+         * reply is processed, so new subscriptions cannot be mixed with the pending state before its bus
+         * instance is validated. A synchronous call is not OK here: this is reached on every
+         * (re-)connection attempt, and if the D-Bus socket unit is
+         * listening while the message bus daemon behind it is gone (e.g. it crashed during shutdown while
+         * we still consider its service to be up), a synchronous call over the never-answered connection
+         * blocks the whole manager for BUS_AUTH_TIMEOUT — repeatedly, since every queued bus operation
+         * triggers another reconnection attempt. The previous connection's instance ID is meaningless for
+         * this connection, hence reset it: only ever populate the live ID from the reply, while any pending
+         * validation ID and subscription state remain serializable across a racing reload/reexec. */
+        m->bus_id = SD_ID128_NULL;
+        r = sd_bus_call_method_async(
+                        bus,
+                        /* ret_slot= */ NULL,
+                        "org.freedesktop.DBus",
+                        "/org/freedesktop/DBus",
+                        "org.freedesktop.DBus",
+                        "GetId",
+                        api_bus_instance_id_reply,
+                        m,
+                        /* types= */ NULL);
+        if (r < 0) {
+                log_full_errno(m->subscribed_as_strv ? LOG_WARNING : LOG_DEBUG, r,
+                               "Failed to enqueue API bus instance ID query%s: %m",
+                               m->subscribed_as_strv ? ", not deserializing subscriptions" : ", ignoring");
+                m->subscribed_as_strv = strv_free(m->subscribed_as_strv);
+                m->deserialized_bus_id = SD_ID128_NULL;
 
-        r = bus_get_instance_id(bus, &m->bus_id);
-        if (r < 0)
-                log_warning_errno(r, "Failed to query API bus instance ID, not deserializing subscriptions: %m");
-        else if (sd_id128_is_null(m->deserialized_bus_id) || sd_id128_equal(m->bus_id, m->deserialized_bus_id))
-                (void) bus_track_coldplug(bus, &m->subscribed, m->subscribed_as_strv);
-        m->subscribed_as_strv = strv_free(m->subscribed_as_strv);
-        m->deserialized_bus_id = SD_ID128_NULL;
+                r = bus_setup_api(m, bus);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to set up API bus: %m");
+        }
 
         m->api_bus = TAKE_PTR(bus);
         return 0;
diff --git a/src/core/manager-serialize.c b/src/core/manager-serialize.c
index efa9f65bfb..7703d63e7a 100644
--- a/src/core/manager-serialize.c
+++ b/src/core/manager-serialize.c
@@ -200,8 +200,10 @@ int manager_serialize(
         (void) serialize_ratelimit(f, "reload-reexec-ratelimit", &m->reload_reexec_ratelimit);
         (void) serialize_ratelimit(f, "event-loop-ratelimit", &m->event_loop_ratelimit);
 
-        (void) serialize_id128(f, "bus-id", m->bus_id);
+        (void) serialize_id128(f, "bus-id",
+                               sd_id128_is_null(m->bus_id) ? m->deserialized_bus_id : m->bus_id);
         bus_track_serialize(m->subscribed, f, "subscribed");
+        (void) serialize_strv(f, "subscribed", m->subscribed_as_strv);
 
         r = dynamic_user_serialize(m, f, fds);
         if (r < 0)
diff --git a/src/core/manager.c b/src/core/manager.c
index f5daa59e1a..ad525539ce 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -3917,8 +3917,10 @@ int manager_override_watchdog_pretimeout_governor(Manager *m, const char *govern
 
 int manager_reload(Manager *m) {
         _unused_ _cleanup_(manager_reloading_stopp) Manager *reloading = NULL;
+        _cleanup_strv_free_ char **saved_subscribed_as_strv = NULL;
         _cleanup_fdset_free_ FDSet *fds = NULL;
         _cleanup_fclose_ FILE *f = NULL;
+        sd_id128_t saved_deserialized_bus_id;
         int r;
 
         assert(m);
@@ -3974,6 +3976,10 @@ int manager_reload(Manager *m) {
         manager_enumerate(m);
 
         /* Second, deserialize our stored data */
+        saved_subscribed_as_strv = TAKE_PTR(m->subscribed_as_strv);
+        saved_deserialized_bus_id = m->deserialized_bus_id;
+        m->deserialized_bus_id = SD_ID128_NULL;
+
         r = manager_deserialize(m, f, fds);
         if (r < 0)
                 log_warning_errno(r, "Deserialization failed, proceeding anyway: %m");
@@ -3987,10 +3993,12 @@ int manager_reload(Manager *m) {
         (void) manager_setup_handoff_timestamp_fd(m);
         (void) manager_setup_pidref_transport_fd(m);
 
-        /* Clean up deserialized bus track information. They're never consumed during reload (as opposed to
-         * reexec) since we do not disconnect from the bus. */
+        /* Discard the bus track information produced by this reload, since the bus stays connected. Preserve
+         * any validation state that was already pending before the reload, so its asynchronous GetId reply can
+         * still consume it when we return to the event loop. */
         m->subscribed_as_strv = strv_free(m->subscribed_as_strv);
-        m->deserialized_bus_id = SD_ID128_NULL;
+        m->subscribed_as_strv = TAKE_PTR(saved_subscribed_as_strv);
+        m->deserialized_bus_id = saved_deserialized_bus_id;
 
         /* Third, fire things up! */
         manager_coldplug(m);
diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c
index 444c4df0fb..f8ff9778b9 100644
--- a/src/shared/bus-util.c
+++ b/src/shared/bus-util.c
@@ -10,7 +10,6 @@
 #include "sd-bus.h"
 #include "sd-daemon.h"
 #include "sd-event.h"
-#include "sd-id128.h"
 
 #include "alloc-util.h"
 #include "bus-common-errors.h"
@@ -916,28 +915,6 @@ int bus_query_sender_pidref(
         return bus_creds_get_pidref(creds, ret);
 }
 
-int bus_get_instance_id(sd_bus *bus, sd_id128_t *ret) {
-        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
-        int r;
-
-        assert(bus);
-        assert(ret);
-
-        r = sd_bus_call_method(bus,
-                               "org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", "GetId",
-                               /* reterr_error= */ NULL, &reply, NULL);
-        if (r < 0)
-                return r;
-
-        const char *id;
-
-        r = sd_bus_message_read_basic(reply, 's', &id);
-        if (r < 0)
-                return r;
-
-        return sd_id128_from_string(id, ret);
-}
-
 static const char* const bus_transport_table[] = {
         [BUS_TRANSPORT_LOCAL]   = "local",
         [BUS_TRANSPORT_REMOTE]  = "remote",
diff --git a/src/shared/bus-util.h b/src/shared/bus-util.h
index c69ed45617..12c2c80081 100644
--- a/src/shared/bus-util.h
+++ b/src/shared/bus-util.h
@@ -70,6 +70,4 @@ int bus_register_malloc_status(sd_bus *bus, const char *destination);
 int bus_creds_get_pidref(sd_bus_creds *c, PidRef *ret);
 int bus_query_sender_pidref(sd_bus_message *m, PidRef *ret);
 
-int bus_get_instance_id(sd_bus *bus, sd_id128_t *ret);
-
 DECLARE_STRING_TABLE_LOOKUP_TO_STRING(bus_transport, BusTransport);