diff --git a/doc/manual/docs/how_to.md b/doc/manual/docs/how_to.md
index b8a83e154..ac1ea4bd5 100644
--- a/doc/manual/docs/how_to.md
+++ b/doc/manual/docs/how_to.md
@@ -85,7 +85,7 @@ ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS | Use [micro-ecc library](https://git
 ENABLE_LE_DATA_CHANNELS          | Enable LE Data Channels in credit-based flow control mode
 ENABLE_LE_DATA_LENGTH_EXTENSION  | Enable LE Data Length Extension support
 ENABLE_LE_SIGNED_WRITE           | Enable LE Signed Writes in ATT/GATT
-ENABLE_ATT_DELAYED_READ_RESPONSE | Enable support for delayed ATT Read operations, see [GATT Server](profiles/#sec:GATTServerProfile)
+ENABLE_ATT_DELAYED_RESPONSE      | Enable support for delayed ATT operations, see [GATT Server](profiles/#sec:GATTServerProfile)
 ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE | Enable L2CAP Enhanced Retransmission Mode. Mandatory for AVRCP Browsing
 ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL | Enable HCI Controller to Host Flow Control, see below
 ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND | Enable workaround for bug in CC256x Flow Control during baud rate change, see chipset docs.
diff --git a/doc/manual/docs/profiles.md b/doc/manual/docs/profiles.md
index 65881b093..57b954e57 100644
--- a/doc/manual/docs/profiles.md
+++ b/doc/manual/docs/profiles.md
@@ -469,7 +469,7 @@ To send a Notification, you can call *att_server_request_can_send_now*
 to receive a ATT_EVENT_CAN_SEND_NOW event.
 
 If your application cannot handle an ATT Read Request in the *att_read_callback*
-in some situations, you can enable support for this by adding ENABLE_ATT_DELAYED_READ_RESPONSE
+in some situations, you can enable support for this by adding ENABLE_ATT_DELAYED_RESPONSE
 to *btstack_config.h*. Now, you can store the requested attribute handle and return
 *ATT_READ_RESPONSE_PENDING* instead of the length of the provided data when you don't have the data ready. 
 For ATT operations that read more than one attribute, your *att_read_callback*
@@ -477,7 +477,7 @@ might get called multiple times as well. To let you know that all necessary
 attribute handles have been 'requested' by the *att_server*, you'll get a final
 *att_read_callback* with the attribute handle of *ATT_READ_RESPONSE_PENDING*.
 When you've got the data for all requested attributes ready, you can call
-*att_server_read_response_ready*, which will trigger processing of the current request.
+*att_server_response_ready*, which will trigger processing of the current request.
 Please keep in mind that there is only one active ATT operation and that it has a 30 second
 timeout after which the ATT server is considered defunct by the GATT Client.
 
diff --git a/example/Makefile.inc b/example/Makefile.inc
index d50431115..733ea5989 100644
--- a/example/Makefile.inc
+++ b/example/Makefile.inc
@@ -108,7 +108,7 @@ HXCMOD_PLAYER = \
 	${BTSTACK_ROOT}/3rd-party/hxcmod-player/mods/nao-deceased_by_disease.c 	\
 
 EXAMPLES = 					\
-	att_delayed_read_response \
+	att_delayed_response \
 	a2dp_sink_demo			\
 	a2dp_source_demo        \
 	ancs_client_demo		\
@@ -207,8 +207,8 @@ spp_counter: ${CORE_OBJ} ${COMMON_OBJ} ${CLASSIC_OBJ} spp_counter.c
 le_counter: le_counter.h ${CORE_OBJ} ${COMMON_OBJ} ${ATT_OBJ} ${GATT_SERVER_OBJ} ${SM_OBJ} battery_service_server.o le_counter.c
 	${CC} $(filter-out le_counter.h,$^) ${CFLAGS} ${LDFLAGS} -o $@
 
-att_delayed_read_response: att_delayed_read_response.h ${CORE_OBJ} ${COMMON_OBJ} ${ATT_OBJ} ${GATT_SERVER_OBJ} ${SM_OBJ} att_delayed_read_response.c
-	${CC} $(filter-out att_delayed_read_response.h,$^) ${CFLAGS} ${LDFLAGS} -o $@
+att_delayed_response: att_delayed_response.h ${CORE_OBJ} ${COMMON_OBJ} ${ATT_OBJ} ${GATT_SERVER_OBJ} ${SM_OBJ} att_delayed_response.c
+	${CC} $(filter-out att_delayed_response.h,$^) ${CFLAGS} ${LDFLAGS} -o $@
 
 hog_keyboard_demo: hog_keyboard_demo.h ${CORE_OBJ} ${COMMON_OBJ} ${ATT_OBJ} ${GATT_SERVER_OBJ} ${SM_OBJ} battery_service_server.o device_information_service_server.o hids_device.o btstack_ring_buffer.o hog_keyboard_demo.c
 	${CC} $(filter-out hog_keyboard_demo.h,$^) ${CFLAGS} ${LDFLAGS} -o $@
diff --git a/example/att_delayed_read_response.gatt b/example/att_delayed_read_response.gatt
deleted file mode 100644
index c7a8399fa..000000000
--- a/example/att_delayed_read_response.gatt
+++ /dev/null
@@ -1,10 +0,0 @@
-PRIMARY_SERVICE, GAP_SERVICE
-CHARACTERISTIC, GAP_DEVICE_NAME, READ, "LE Counter"
-
-PRIMARY_SERVICE, GATT_SERVICE
-CHARACTERISTIC, GATT_SERVICE_CHANGED, READ,
-
-// Counter Service
-PRIMARY_SERVICE, 0000FF10-0000-1000-8000-00805F9B34FB
-// Counter Characteristic, with read and notify
-CHARACTERISTIC,  0000FF11-0000-1000-8000-00805F9B34FB, READ | NOTIFY | DYNAMIC,
diff --git a/example/att_delayed_read_response.c b/example/att_delayed_response.c
similarity index 74%
rename from example/att_delayed_read_response.c
rename to example/att_delayed_response.c
index 58035a06a..3bde9c51a 100644
--- a/example/att_delayed_read_response.c
+++ b/example/att_delayed_response.c
@@ -35,14 +35,18 @@
  *
  */
 
-#define __BTSTACK_FILE__ "att_delayed_read_response.c"
+#define __BTSTACK_FILE__ "att_delayed_response.c"
 
 // *****************************************************************************
-/* EXAMPLE_START(att_delayed_read_response): LE Peripheral - Delayed Read Response
+/* EXAMPLE_START(att_delayed_response): LE Peripheral - Delayed Response
  *
- * @text If the value for a GATT Chararacteristic isn't available, the value
- * ATT_READ_RESPONSE_PENDING can be returned. When the value is available, 
- * att_server_read_response_ready is then called to complete the ATT request.
+ * @text If the value for a GATT Chararacteristic isn't availabl for read,
+ * the value ATT_READ_RESPONSE_PENDING can be returned. When the value is available, 
+ * att_server_response_ready is then called to complete the ATT request.
+ * 
+ * Similarly, the error code ATT_ERROR_WRITE_RESPONSE_PENING can be returned when
+ * it is unclear if a write can be performed or not. When the decision was made,
+ * att_server_response_ready is is then called to complete the ATT request.
  */
  // *****************************************************************************
 
@@ -51,7 +55,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "att_delayed_read_response.h"
+#include "att_delayed_response.h"
 #include "btstack.h"
 
 #define ATT_VALUE_DELAY_MS   3000
@@ -69,19 +73,20 @@
  */
  
 /* LISTING_START(MainConfiguration): Init L2CAP SM ATT Server */
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
 static btstack_timer_source_t att_timer;
 static hci_con_handle_t con_handle;
 static int value_ready;
 #endif
 
 static uint16_t att_read_callback(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size);
+static int att_write_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size);
 
 const uint8_t adv_data[] = {
     // Flags general discoverable, BR/EDR not supported
     0x02, 0x01, 0x06, 
     // Name
-    0x0b, 0x09, 'L', 'E', ' ', 'C', 'o', 'u', 'n', 't', 'e', 'r', 
+    0x08, 0x09, 'D', 'e', 'l', 'a', 'y', 'e', 'd', 
 };
 const uint8_t adv_data_len = sizeof(adv_data);
 
@@ -98,7 +103,7 @@ static void example_setup(void){
     sm_init();
 
     // setup ATT server
-    att_server_init(profile_data, att_read_callback, NULL);
+    att_server_init(profile_data, att_read_callback, att_write_callback);
 
     // setup advertisements
     uint16_t adv_int_min = 0x0030;
@@ -117,7 +122,7 @@ static void example_setup(void){
  *
  * @text The att_invalidate_value handler 'invalidates' the value of the single Characteristic provided in this example
  */
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
 static void att_invalidate_value(struct btstack_timer_source *ts){
     UNUSED(ts);
     printf("Value got stale\n");
@@ -132,14 +137,13 @@ static void att_invalidate_value(struct btstack_timer_source *ts){
  */
 
  /* LISTING_START(att_read_delay): ATT Read Delay Handler */
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
 static void att_update_value(struct btstack_timer_source *ts){
     UNUSED(ts);
     value_ready = 1;
 
-
     // trigger ATT Server to try request again
-    int status = att_server_read_response_ready(con_handle);
+    int status = att_server_response_ready(con_handle);
 
     printf("Value updated -> complete ATT request - status %02x\n", status);
 
@@ -169,7 +173,7 @@ static void att_update_value(struct btstack_timer_source *ts){
 // @param offset defines start of attribute value
 static uint16_t att_read_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size){
 
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
     switch (att_handle){
         case ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE:
             if (value_ready){
@@ -193,15 +197,50 @@ static uint16_t att_read_callback(hci_con_handle_t connection_handle, uint16_t a
     }
 #else
     UNUSED(connection_handle);
-    // useless code when ENABLE_ATT_DELAYED_READ_RESPONSE is not defined - but avoids built errors
+    // useless code when ENABLE_ATT_DELAYED_RESPONSE is not defined - but avoids built errors
     if (att_handle == ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE){
-        printf("ENABLE_ATT_DELAYED_READ_RESPONSE not defined in btstack_config.h, responding right away");
+        printf("ENABLE_ATT_DELAYED_RESPONSE not defined in btstack_config.h, responding right away");
         return att_read_callback_handle_blob((const uint8_t *)test_string, strlen(test_string), offset, buffer, buffer_size);
     }
 #endif
 
     return 0;
 }
+
+/*
+ * @section ATT Write
+ * */
+
+/* LISTING_START(attWrite): ATT Write */
+static int att_write_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){
+    UNUSED(transaction_mode);
+    UNUSED(offset);
+    UNUSED(buffer_size);
+    UNUSED(connection_handle);
+    
+    if (att_handle == ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE) {
+        printf("Write request, value: ");
+        printf_hexdump(buffer, buffer_size);
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
+        if (value_ready){
+            printf("Write callback, value ready\n");
+            return 0;                    
+        } else {
+            printf("Write callback for handle %02x, but not ready -> return response pending\n", att_handle);
+        }
+        // simulated delayed response for example
+        att_timer.process = &att_update_value;
+        btstack_run_loop_set_timer(&att_timer, ATT_VALUE_DELAY_MS);
+        btstack_run_loop_add_timer(&att_timer);
+        return ATT_ERROR_WRITE_RESPONSE_PENDING;
+#else
+        printf("ENABLE_ATT_DELAYED_RESPONSE not defined in btstack_config.h, responding right away");
+        return 0;
+#endif
+    }
+    return 0;
+}
+
 /* LISTING_END */
 
 int btstack_main(void);
diff --git a/example/att_delayed_response.gatt b/example/att_delayed_response.gatt
new file mode 100644
index 000000000..268db34a4
--- /dev/null
+++ b/example/att_delayed_response.gatt
@@ -0,0 +1,10 @@
+PRIMARY_SERVICE, GAP_SERVICE
+CHARACTERISTIC, GAP_DEVICE_NAME, READ, "Delayed Response"
+
+PRIMARY_SERVICE, GATT_SERVICE
+CHARACTERISTIC, GATT_SERVICE_CHANGED, READ,
+
+// Some Service
+PRIMARY_SERVICE, 0000FF10-0000-1000-8000-00805F9B34FB
+// Some Characteristic, with read and write
+CHARACTERISTIC,  0000FF11-0000-1000-8000-00805F9B34FB, READ | WRITE | DYNAMIC,
diff --git a/port/libusb/.gitignore b/port/libusb/.gitignore
index 1dbd6f313..99852154a 100644
--- a/port/libusb/.gitignore
+++ b/port/libusb/.gitignore
@@ -61,6 +61,5 @@ spp_and_le_streamer.h
 spp_counter
 spp_streamer
 spp_streamer_client
-spp_streamer_client
-att_delayed_read_response
-att_delayed_read_response.h
+att_delayed_response
+att_delayed_response.h
diff --git a/port/libusb/btstack_config.h b/port/libusb/btstack_config.h
index 7056a8244..66d77ad64 100644
--- a/port/libusb/btstack_config.h
+++ b/port/libusb/btstack_config.h
@@ -21,7 +21,7 @@
 #define ENABLE_LE_DATA_CHANNELS
 #define ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS
 #define ENABLE_LE_DATA_LENGTH_EXTENSION
-#define ENABLE_ATT_DELAYED_READ_RESPONSE
+#define ENABLE_ATT_DELAYED_RESPONSE
 #define ENABLE_LOG_ERROR
 #define ENABLE_LOG_INFO 
 #define ENABLE_SCO_OVER_HCI
diff --git a/port/posix-h4-da14581/.gitignore b/port/posix-h4-da14581/.gitignore
index eb6db3145..e0485af4e 100644
--- a/port/posix-h4-da14581/.gitignore
+++ b/port/posix-h4-da14581/.gitignore
@@ -47,5 +47,5 @@ le_streamer_client
 pbap_client_demo
 sm_pairing_central
 sm_pairing_peripheral
-
+att_delayed_read_response
 att_delayed_read_response.h
diff --git a/port/posix-h4-da14585/.gitignore b/port/posix-h4-da14585/.gitignore
index eb6db3145..ec221219e 100644
--- a/port/posix-h4-da14585/.gitignore
+++ b/port/posix-h4-da14585/.gitignore
@@ -1,5 +1,6 @@
 ancs_client_demo
 ancs_client_demo.h
+att_delayed_response.h
 ble_central_test
 ble_peripheral
 ble_peripheral_sm_minimal
@@ -16,7 +17,9 @@ gap_inquiry
 gap_inquiry_and_bond
 gap_le_advertisements
 gatt_battery_query
+gatt_battery_query.h
 gatt_browser
+gatt_browser.h
 hfp_ag_demo
 hfp_hf_demo
 hsp_ag_demo
@@ -28,12 +31,16 @@ le_counter
 le_counter.h
 le_streamer
 le_streamer.h
+le_streamer_client
 led_counter
+pbap_client_demo
 profile.h
 sco_input.wav
 sdp_bnep_query
 sdp_general_query
 sdp_rfcomm_query
+sm_pairing_central
+sm_pairing_peripheral
 sm_pairing_peripheral.h
 spp_and_le_counter
 spp_and_le_counter.h
@@ -41,11 +48,3 @@ spp_counter
 spp_streamer
 TIInit_12.10.28.c
 TIInit_12.8.32.c
-gatt_battery_query.h
-gatt_browser.h
-le_streamer_client
-pbap_client_demo
-sm_pairing_central
-sm_pairing_peripheral
-
-att_delayed_read_response.h
diff --git a/port/posix-h4/btstack_config.h b/port/posix-h4/btstack_config.h
index 3e1d2191c..c80506ea3 100644
--- a/port/posix-h4/btstack_config.h
+++ b/port/posix-h4/btstack_config.h
@@ -22,7 +22,7 @@
 #define ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS
 #define ENABLE_LE_DATA_CHANNELS
 #define ENABLE_LE_DATA_LENGTH_EXTENSION
-#define ENABLE_ATT_DELAYED_READ_RESPONSE
+#define ENABLE_ATT_DELAYED_RESPONSE
 #define ENABLE_LOG_ERROR
 #define ENABLE_LOG_INFO 
 #define ENABLE_SCO_OVER_HCI
diff --git a/src/ble/att_db.h b/src/ble/att_db.h
index eb39516e3..bcb745d37 100644
--- a/src/ble/att_db.h
+++ b/src/ble/att_db.h
@@ -54,8 +54,9 @@ extern "C" {
 // custom BTstack ATT error codes
 #define ATT_ERROR_DATA_MISMATCH                   0x7e
 #define ATT_ERROR_TIMEOUT                         0x7F
+#define ATT_ERROR_WRITE_RESPONSE_PENDING         0x100
 
-// custom BTstack ATT Response Pending 
+// custom BTstack ATT Response Pending for att_read_callback
 #define ATT_READ_RESPONSE_PENDING                 0xffff
 
 typedef struct att_connection {
diff --git a/src/ble/att_server.c b/src/ble/att_server.c
index 7f2fcbb2f..e8080f2f3 100644
--- a/src/ble/att_server.c
+++ b/src/ble/att_server.c
@@ -386,10 +386,10 @@ static int att_server_process_validated_request(att_server_t * att_server){
     uint8_t * att_response_buffer = l2cap_get_outgoing_buffer();
     uint16_t  att_response_size   = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer);
 
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
     if (att_response_size == ATT_READ_RESPONSE_PENDING){
         // update state
-        att_server->state = ATT_SERVER_READ_RESPONSE_PENDING;
+        att_server->state = ATT_SERVER_RESPONSE_PENDING;
 
         // callback with handle ATT_READ_RESPONSE_PENDING
         att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0);
@@ -434,11 +434,11 @@ static int att_server_process_validated_request(att_server_t * att_server){
     return 1;
 }
 
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
-int att_server_read_response_ready(hci_con_handle_t con_handle){
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
+int att_server_response_ready(hci_con_handle_t con_handle){
     att_server_t * att_server = att_server_for_handle(con_handle);
-    if (!att_server)                                             return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
-    if (att_server->state != ATT_SERVER_READ_RESPONSE_PENDING)   return ERROR_CODE_COMMAND_DISALLOWED;
+    if (!att_server)                                        return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
+    if (att_server->state != ATT_SERVER_RESPONSE_PENDING)   return ERROR_CODE_COMMAND_DISALLOWED;
 
     att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED;
     att_dispatch_server_request_can_send_now_event(con_handle);
diff --git a/src/ble/att_server.h b/src/ble/att_server.h
index 55e4a37c0..c70bed378 100644
--- a/src/ble/att_server.h
+++ b/src/ble/att_server.h
@@ -135,14 +135,15 @@ int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, ui
  */
 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t *value, uint16_t value_len);
 
-#ifdef ENABLE_ATT_DELAYED_READ_RESPONSE
+#ifdef ENABLE_ATT_DELAYED_RESPONSE
 /*
- * @brief read response ready - called after returning ATT_READ_RESPONSE_PENDING in an att_read_callback before
+ * @brief response ready - called after returning ATT_READ__RESPONSE_PENDING in an att_read_callback or
+ * ATT_ERROR_WRITE_REQUEST_PENDING IN att_write_callback before to trigger callback again and complete the transaction
  * @nore The ATT Server will retry handling the current ATT request
  * @param con_handle
  * @return 0 if ok, error otherwise
  */
-int att_server_read_response_ready(hci_con_handle_t con_handle);
+int att_server_response_ready(hci_con_handle_t con_handle);
 #endif
 
 /* API_END */
diff --git a/src/hci.h b/src/hci.h
index c29e8ccd3..3e7926157 100644
--- a/src/hci.h
+++ b/src/hci.h
@@ -410,7 +410,7 @@ typedef enum {
     ATT_SERVER_REQUEST_RECEIVED,
     ATT_SERVER_W4_SIGNED_WRITE_VALIDATION,
     ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED,
-    ATT_SERVER_READ_RESPONSE_PENDING,
+    ATT_SERVER_RESPONSE_PENDING,
 } att_server_state_t;
 
 typedef struct {