Examination on filing – accordance of the date of filing
136
On receiving an application the Receiving Section examines whether it can be accorded a date of filing. This is the case if the application documents contain: 
an indication that a European patent is sought 
information identifying the applicant 
a description or a reference to a previously filed application.
137
It is not necessary to file any claims in order to obtain a date of filing. You may file claims within two months fromafter the date of filing on your own motioninitiative or within two months from the date of filing or from an invitation requesting you to do so. However, you should take care that the late-filed claims do not contain subject-matter which extends beyond the content of the application as originally filed.
138
If a date of filing cannot be accorded because If any of the requirements mentioned in point 135 have not been fulfilled, a date of filing cannot be accorded. The EPO’s Receiving Section will inform you accordingly and invite you to remedy the deficiency/any deficiencies found within a non-extendable time limit of two months. If you file a timely response and remedy the deficiency/deficiencies, the date of receipt of your response will be the accorded date of filing of the application. If you do not file a (timely) response have not been remedied in due time despite an invitation to do so, the application will not be dealt with as a European patent application.
For a date of filing to be accorded, the documents do not have to meet any particular requirements as to form or presentation. It is essential, however, that they be sufficiently legible to enable the information to be discerned. 

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