The entry into force of the agreement between the European and the Chinese patent offices on the electronic exchange of priority documents (also known as the PDX agreement) on 3rd September 2012 will hail a major milestone in bilateral co-operation between both organizations.

Under the agreement, priority documents are exchanged via the PDX system over PatNet, using the Trilateral Data Access protocol (TDA).


The entry into force of the EPO-SIPO PDX agreement will reduce the administrative costs associated with processing received paper copies of priority documents and storing them in electronic record management systems. As of 3 September 2012, EPO and SIPO applicants and attorneys will be able to reduce the cost of ordering certified paper copies of priority documents from the Office of First Filing (OFF) and to provide these documents to the Office of Second Filing (OSF) in a more timely manner.

Implementation of the PDX agreement will also support the patent granting process and ease the way to online collaboration between the EPO and SIPO, thereby contributing to improvements in the quality of European patent files.


On 5th December 2010, SIPO Commissioner Tian Lipu and EPO President Benoît Battistelli signed a bilateral agreement enabling the electronic exchange of priority documents. The agreement imposes a legal responsibility on SIPO and the EPO to facilitate the exchange of priority document between the two offices. It forms part of the “EPO-SIPO Bilateral Co-operation Annual Work Programme 2012″.

The right of priority established by Article 4 of the Paris Convention for the Protection of Industrial Property is a central feature of the international patent system. Priority claims in patent applications need to be backed up by reliable copies of the earlier applications from which priority is claimed. Certified copies of such applications are routinely required by patent offices under the applicable national or regional laws as a condition for the recognition of priority rights, in accordance with Article 4D of the Paris Convention.

Next steps

In the future, the two offices will work on maintenance of the PDX agreement and will investigate the possibility of extending electronic exchange to other types of document and thus expanding the electronic exchange of patent information between the two offices.

Further information

Decision of the President of the European Patent Office dated 9 August 2012 on the filing of priority documents (OJ EPO 2012, 492).

Notice from the European Patent Office dated 9 August 2012 regarding the automatic exchange of priority documents between the European Patent Office and the State Intellectual Property Office of the People’s Republic of China (OJ EPO 2012, 494).