14. Determination procedures should adopt an approach to evidence which takes into account the challenges inherent in establishing whether a person is stateless. The evidentiary requirements should not be so onerous as to defeat the object and purpose of the 1954 Convention by preventing stateless persons from being recognized. It is only necessary to consider nationality in relation to States with which an individual applicant has relevant links (in particular by birth on the territory, descent, marriage or habitual residence). 15. While possession of a passport may raise a presumption of nationality, this is rebuttable as some countries issue “passports of convenience” to individuals who are not their nationals. 16. Determining statelessness requires an examination of the practice as well as the law in relation to nationality in the relevant State(s). As such, it is essential that the determining official has access to credible, accurate, and contemporary information. This may be gleaned from a variety of sources – governmental and non-governmental – and cooperation between States and other actors in setting up reliable database(s) of nationality laws and practice should be encouraged. Contacting foreign authorities 17. Information provided by foreign authorities is sometimes of central importance for determinations on statelessness. However, contact with such authorities does not need to be sought in every case, in particular where there are already adequate elements of proof. Under no circumstances should contact be made with authorities of a State against which an individual alleges a well-founded fear of persecution unless it has definitively been concluded that he or she is not a refugee or entitled to a complementary form of protection. 18. Flexibility may be necessary in relation to the procedures for making contact with foreign authorities to confirm whether or not an individual is its national. Some foreign authorities will only accept inquiries that come directly from another State while others are only open to contact from individuals. In some cases UNHCR’s assistance in making contact with, and obtaining a response from, foreign authorities may be necessary and the Office should offer its support in this regard as appropriate. 19. When contacting foreign authorities, States may set time-limits for a response as it is in the interest of both States and stateless applicants that statelessness determination proceedings be expeditious. However, some cases might present particularly complex circumstances that will require more time for resolution. Additional time may be warranted, in particular where there is evidence that an individual may in fact be a national of a specific State but has yet to receive official attestation of this. 5