diff --git a/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.png b/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.png
index c74ec06a4c..af27574124 100644
Binary files a/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.png and b/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.png differ
diff --git a/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.txt b/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.txt
index 286fcbe813..f37e937303 100644
--- a/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.txt
+++ b/docs/design-documents/nfc/uml_diagram_ndef_message_builder_diagram.txt
@@ -3,12 +3,15 @@
 package ndef {
 
 class MessageBuilder { 
-    +MessageBuilder(uint8_t* buffer, size_t capacity)
+    +MessageBuilder(const Span<uint8_t> &buffer)
     +~MessageBuilder()
-    +bool append_record(const RecordType& type, const RecordPayload* payload, bool is_last_record = false)
-    +bool append_record(const Record& record)
-    +const uint8_t* get_data() const;
-    +size_t get_data_size() const;
+    +bool append_record(const RecordType &type, const RecordPayload &payload = RecordPayload(), bool is_last_record = false)
+    +bool append_record(const RecordType &type, const PayloadBuilder &builder, bool is_last_record = false)
+    +bool append_record(const Record &record, const PayloadBuilder *builder = NULL)
+    +void reset();
+    +void reset(const Span<uint8_t> &buffer);
+    +bool is_message_complete() const
+    +Span<const uint8_t> get_message() const
 }
 
 class Record { 
@@ -23,41 +26,40 @@ class RecordPayload{
 class RecordID{
 }
 
+interface MessageBuilder::PayloadBuilder { 
+    +{abstract} size_t size() const
+    +{abstract} void build(const Span<uint8_t> &buffer) const
+    # ~PayloadBuilder()
+}
+
+
 Record *-- RecordType
 Record *-- "0..1" RecordPayload
 Record *-- "0..1" RecordID
 
 Record - MessageBuilder: insert >
+MessageBuilder - MessageBuilder::PayloadBuilder: < build payload at insertion
 
 }
 
 package common { 
 
-class SimpleMessageBuilder { 
-    +SimpleMessageBuilder(uint8_t* buffer, size_t capacity)
-    +~SimpleMessageBuilder()
-    +bool append_uri(const URI&)
-    +bool append_text(const Text&)
-    +bool append_mime(const Mime&)
-} 
 
 class URI { 
-+friend bool append_record(ndef::MessageBuilder&, const URI&)
++bool append_as_record(ndef::MessageBuilder &builder, bool is_last_record) const
 }
 
 class Text { 
-+friend bool append_record(ndef::MessageBuilder&, const Text&)
++bool append_as_record(ndef::MessageBuilder &builder, bool is_last_record) const
 }
 
 class Mime { 
-+friend bool append_record(ndef::MessageBuilder&, const Mime&)
++bool append_as_record(ndef::MessageBuilder &builder, bool is_last_record) const
 }
 
-SimpleMessageBuilder --|> MessageBuilder
-
-URI -- SimpleMessageBuilder: wrap >
-Text -- SimpleMessageBuilder: wrap >
-Mime -- SimpleMessageBuilder: wrap >
+URI -- MessageBuilder: uses >
+Text -- MessageBuilder: uses >
+Mime -- MessageBuilder: uses >
 
 }
 
diff --git a/docs/design-documents/nfc/uml_diagram_ndef_message_parser.png b/docs/design-documents/nfc/uml_diagram_ndef_message_parser.png
index ab27b91474..96b906cf2b 100644
Binary files a/docs/design-documents/nfc/uml_diagram_ndef_message_parser.png and b/docs/design-documents/nfc/uml_diagram_ndef_message_parser.png differ
diff --git a/docs/design-documents/nfc/uml_diagram_ndef_message_parser.txt b/docs/design-documents/nfc/uml_diagram_ndef_message_parser.txt
index c5761290fa..3030efd01f 100644
--- a/docs/design-documents/nfc/uml_diagram_ndef_message_parser.txt
+++ b/docs/design-documents/nfc/uml_diagram_ndef_message_parser.txt
@@ -4,13 +4,13 @@ package ndef {
 
 class MessageParser { 
     +MessageParser()
-    +void set_delegate(Delegate* delegate)
-    +void parse(const ac_buffer_t& data_buffer)
+    +void set_delegate(Delegate *delegate)
+    +void parse(const Span<const uint8_t> &data_buffer)
 }
 
 interface MessageParser::Delegate { 
     +{abstract} void on_parsing_started()
-    +{abstract} void on_record_parsed(const Record& record)
+    +{abstract} void on_record_parsed(const Record &record)
     +{abstract} void on_parsing_terminated()
     +{abstract} void on_parsing_error(error_t error)
     # ~Delegate()
diff --git a/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.png b/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.png
index 02a77eb114..7e2a9fd5e7 100644
Binary files a/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.png and b/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.png differ
diff --git a/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.txt b/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.txt
index d1618f8dc6..ff77ce4dda 100644
--- a/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.txt
+++ b/docs/design-documents/nfc/uml_diagram_ndef_simple_parser.txt
@@ -48,26 +48,26 @@ package common {
 class SimpleMessageParser { 
     + SimpleMessageParser()
     + ~SimpleMessageParser()
-    + void set_delegate(Delegate* delegate)
-    + void parse(const ac_buffer_t& data_buffer)
-    + void add_record_parser(ndef::RecordParser* parser)
+    + void set_delegate(Delegate *delegate)
+    + void parse(const Span<const uint8_t> &data_buffer)
+    + void add_record_parser(ndef::RecordParser *parser)
     - void on_parsing_error(ndef::MessageParser::error_t error)
     - void on_parsing_started()
-    - void on_record_parsed(const ndef::Record& record)
+    - void on_record_parsed(const ndef::Record &record)
     - void on_parsing_terminated()
-    - void on_record_parsed(const URI& uri, const ndef::RecordID* id)
-    - void on_record_parsed(const Text& uri, const ndef::RecordID* id)
-    - void on_record_parsed(const Mime& uri, const ndef::RecordID* id)
+    - void on_record_parsed(const URI &uri, const ndef::RecordID &id)
+    - void on_record_parsed(const Text &uri, const ndef::RecordID &id)
+    - void on_record_parsed(const Mime &uri, const ndef::RecordID &id)
 }
 
 interface SimpleMessageParser::Delegate {     
-    + {abstract} void on_parsing_error(ndef::MessageParser::error_t error)
     + {abstract} void on_parsing_started() 
-    + {abstract} void on_text_parsed(const Text& text, const ndef::RecordID* id)
-    + {abstract} void on_mime_parsed(const Mime& text, const ndef::RecordID* id)
-    + {abstract} void on_uri_parsed(const URI& uri, const ndef::RecordID* id)
-    + {abstract} void on_unknown_record_parsed(const ndef::Record& record)
+    + {abstract} void on_text_parsed(const Text &text, const ndef::RecordID &id)
+    + {abstract} void on_mime_parsed(const Mime &text, const ndef::RecordID &id)
+    + {abstract} void on_uri_parsed(const URI &uri, const ndef::RecordID &id)
+    + {abstract} void on_unknown_record_parsed(const ndef::Record &record)
     + {abstract} void on_parsing_terminated()
+    + {abstract} void on_parsing_error(ndef::MessageParser::error_t error)    
     # ~Delegate()
 }