diff --git a/odoo/tools/pdf.py b/odoo/tools/pdf.py
index 61105ed1c90..9003ad64789 100644
--- a/odoo/tools/pdf.py
+++ b/odoo/tools/pdf.py
@@ -1,25 +1,37 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
-import io
-import PyPDF2
+from PyPDF2 import PdfFileWriter, PdfFileReader
+from PyPDF2.generic import DictionaryObject, DecodedStreamObject, NameObject, createStringObject, ArrayObject
+from PyPDF2.utils import b_
+from datetime import datetime
 
-class BrandedFileWriter(PyPDF2.PdfFileWriter):
+import io
+import hashlib
+
+
+DEFAULT_PDF_DATETIME_FORMAT = "D:%Y%m%d%H%M%S+00'00'"
+
+
+class BrandedFileWriter(PdfFileWriter):
     def __init__(self):
         super().__init__()
         self.addMetadata({
             '/Creator': "Odoo",
             '/Producer': "Odoo",
         })
-PyPDF2.PdfFileWriter = BrandedFileWriter
+
+
+PdfFileWriter = BrandedFileWriter
+
 
 def merge_pdf(pdf_data):
     ''' Merge a collection of PDF documents in one
     :param list pdf_data: a list of PDF datastrings
     :return: a unique merged PDF datastring
     '''
-    writer = PyPDF2.PdfFileWriter()
+    writer = PdfFileWriter()
     for document in pdf_data:
-        reader = PyPDF2.PdfFileReader(io.BytesIO(document), strict=False)
+        reader = PdfFileReader(io.BytesIO(document), strict=False)
         for page in range(0, reader.getNumPages()):
             writer.addPage(reader.getPage(page))
     with io.BytesIO() as _buffer:
@@ -32,8 +44,8 @@ def rotate_pdf(pdf):
     :param pdf: a PDF to rotate
     :return: a PDF rotated
     '''
-    writer = PyPDF2.PdfFileWriter()
-    reader = PyPDF2.PdfFileReader(io.BytesIO(pdf), strict=False)
+    writer = PdfFileWriter()
+    reader = PdfFileReader(io.BytesIO(pdf), strict=False)
     for page in range(0, reader.getNumPages()):
         page = reader.getPage(page)
         page.rotateClockwise(90)
@@ -41,3 +53,67 @@ def rotate_pdf(pdf):
     with io.BytesIO() as _buffer:
         writer.write(_buffer)
         return _buffer.getvalue()
+
+
+class OdooPdfFileReader(PdfFileReader):
+    # OVERRIDE of PdfFileReader to add the management of multiple embedded files.
+
+    def getAttachments(self):
+        if "/Names" not in self.trailer["/Root"]:
+            return []
+        for i in range(0, len(self.trailer["/Root"]["/Names"]["/EmbeddedFiles"]["/Names"]), 2):
+            attachment = self.trailer["/Root"]["/Names"]["/EmbeddedFiles"]["/Names"][i+1].getObject()
+            yield (attachment["/F"], attachment["/EF"]["/F"].getObject().getData())
+
+
+class OdooPdfFileWriter(PdfFileWriter):
+    # OVERRIDE of PdfFileWriter to add the management of multiple embedded files.
+
+    def _create_attachment_object(self, attachment):
+        ''' Create a PyPdf2.generic object representing an embedded file.
+
+        :param attachment: A dictionary containing:
+            * filename: The name of the file to embed (require).
+            * content:  The content of the file encoded in base64 (require).
+        :return:
+        '''
+        file_entry = DecodedStreamObject()
+        file_entry.setData(attachment['content'])
+        file_entry.update({
+            NameObject("/Type"): NameObject("/EmbeddedFile"),
+            NameObject("/Params"):
+                DictionaryObject({
+                    NameObject('/CheckSum'): createStringObject(hashlib.md5(attachment['content']).hexdigest()),
+                    NameObject('/ModDate'): createStringObject(datetime.now().strftime(DEFAULT_PDF_DATETIME_FORMAT)),
+                    NameObject('/Size'): NameObject(str(len(attachment['content']))),
+                }),
+        })
+        if attachment.get('subtype'):
+            file_entry.update({
+                NameObject("/Subtype"): NameObject(attachment['subtype']),
+            })
+        file_entry_object = self._addObject(file_entry)
+        filename_object = createStringObject(attachment['filename'])
+        filespec_object = DictionaryObject({
+            NameObject("/AFRelationship"): NameObject("/Data"),
+            NameObject("/Type"): NameObject("/Filespec"),
+            NameObject("/F"): filename_object,
+            NameObject("/EF"):
+                DictionaryObject({
+                    NameObject("/F"): file_entry_object,
+                    NameObject('/UF'): file_entry_object,
+                }),
+            NameObject("/UF"): filename_object,
+        })
+        if attachment.get('description'):
+            filespec_object.update({NameObject("/Desc"): createStringObject(attachment['description'])})
+        return self._addObject(filespec_object)
+
+    def addAttachment(self, fname, fdata):
+        # OVERRIDE of the AddAttachment method to allow appending attachemnts when some already exist
+        if self._root_object.get('/Names') and self._root_object['/Names'].get('/EmbeddedFiles'):
+            attachments = self._root_object["/Names"]["/EmbeddedFiles"]["/Names"]
+            new_attachment = self._create_attachment_object({'filename': fname, 'content': fdata})
+            attachments.extend([new_attachment.getObject()['/F'], new_attachment])
+        else:
+            super().addAttachment(fname, fdata)