Since there is no shared ID database between the European Union and the countries of origin (such as Syria), the police / border patrol authorities of the EU countries involved tend to base their decisions on the following criteria:
- ID card or other official documents shown by the refugee, if any;
- identification of the specific dialect or language, e.g. a Syrian dialect of the Arabic language, via specialized interpreters;
- if anything else fails, they rely upon the statements made by the refugee, provided they are credible and consistent.
As an example, a 2013 UNCHR report states:
Moreover, guidance also provides that the determining [Dutch] authority may assist the applicant by conducting, for example, a language analysis, an examination of the validity of documents, an age assessment, and obtaining an individual country report. Such steps have been viewed by the courts as compensating for the evidentiary difficulties faced by applicants.
Similar procedures are quoted in several documents from different EU countries, including the United Kingdom, which in a January 2015 official document explains:
Evidence includes - but is not limited to:
Screening Interview (SIR);
Statements made to an Immigration Officer prior to the claim being made, or information supplied when he/she applied for a visa;
Other evidence submitted by the claimant, e.g. written statements, newspaper or Internet articles, witness statements from family or associates, police or medical reports, political party membership cards
Country of origin information (COI)
Files relating to previous applications by the claimant or his/her relatives
Passports: where available, checked for entry/exit stamps, visas, to confirm the claimant's immigration status and history
Other expert evidence