The national law of an EPC contracting state may stipulate that, for national security reasons, an international application must be filed with the EPO as receiving Office via a competent authority of that state.[Art. 75(2); 151 EPC; R. 157(1); (3) EPC; R. 19.1(b); ]

In such cases, the national authority will act as the "filing office" for the EPO acting as receiving Office. The date of receipt of the application by the national authority will be considered to be the international filing date, provided that the application meets the PCT requirements for a filing date to be accorded (see GL/PCT‑EPO A‑II, 4.1).

The national authority must ensure that the application reaches the EPO not later than two weeks before the end of the 13th month from filing or, if priority is claimed, from the earliest date of priority. For further details, see GL/RO Chapter III.