diff --git a/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp b/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
index ea1dacda32..af62b211bf 100644
--- a/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
+++ b/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
@@ -475,6 +475,11 @@ void BluetoothProxy::loop() {
   for (uint8_t i = 0; i < this->connection_count_; i++) {
     this->connections_[i]->process_pending_services();
   }
+  if (this->connections_free_pending_ && this->api_connection_ != nullptr) {
+    // Resend a dropped slot-state update once the TCP buffer drains.
+    this->connections_free_pending_ = false;
+    this->send_connections_free(this->api_connection_);
+  }
 #endif
 
   // Run advertisement flush / scanner-state poll every 100ms
@@ -629,7 +634,10 @@ void BluetoothProxy::send_connections_free() {
 }
 
 void BluetoothProxy::send_connections_free(api::APIConnection *api_connection) {
-  api_connection->send_message(this->connections_free_response_);
+  if (!api_connection->send_message(this->connections_free_response_)) {
+    ESP_LOGD(TAG, "Connections-free update deferred, TCP buffer full");
+    this->connections_free_pending_ = true;
+  }
 }
 
 void BluetoothProxy::send_gatt_services_done(uint64_t address) {
diff --git a/esphome/components/bluetooth_proxy/bluetooth_proxy.h b/esphome/components/bluetooth_proxy/bluetooth_proxy.h
index 17e480b671..26f99fcca2 100644
--- a/esphome/components/bluetooth_proxy/bluetooth_proxy.h
+++ b/esphome/components/bluetooth_proxy/bluetooth_proxy.h
@@ -254,6 +254,10 @@ class BluetoothProxy final : public Component {
 
   // Group 4: 1-byte types grouped together
   bool active_;
+  // A dropped send (full TCP buffer) would leave the API client with a stale
+  // slot state forever; the cached response is current by construction, so
+  // retrying it from loop() is an idempotent resync.
+  bool connections_free_pending_{false};
   uint8_t connection_count_{0};
   bool configured_scan_active_{false};  // Configured scan mode from YAML
 #ifndef USE_BLE_SCANNER_STATE_CALLBACK