An important principle in EU law is the concept of abuse of rights, as the exercise of Treaty rights by individuals may require EU Member States to ignore their own national laws.
In the UK, the Home Office will sometimes refuse applications if it believes that there is a clear intention to abuse EU rights by an applicant, e.g. where there has been a use of fake payslips or a marriage of convenience (i.e. a sham marriage). The onus is on the Home Office to provide evidence of the lack of genuineness of the applicant‘s employment or marriage.
In IS (marriages of convenience) Serbia  UKAIT 00031, the Asylum and Immigration Tribunal held that the burden of proving that a marriage is not a “marriage of convenience” for the purposes of the EEA Regulations rests on the appellant: however, the appellant is not required to discharge it in the absence of evidence of matters supporting a suspicion that the marriage is one of convenience (i.e. there is an evidential burden on the Respondent Home Office).
In practice when allegations are made that a marriage is a sham, it is usually necessary to show the genuineness of the relationship by providing witnesses who are acquainted with the couple, close family members, best friends, managers, co-workers, etc. Appellants would also be expected to provide proof of communication, itemised bills, or social media information. This list is not exhaustive and will depend on the circumstances surrounding the case.
Particular issues arise time and again in relation to proxy marriages:
1. The appellant must prove that the proxy marriage is lawful in the country in which it was contracted.
2. The appellant has the obligation to prove that their proxy marriage was in accordance with the laws of the country in which it took place and that both parties were free to marry.
In this situation, the production of a marriage certificate duly attested and issued by a competent authority of the country in which the marriage took place, would in some ways satisfy the presumption of validity.
For a long time it was believed that a proxy marriage contracted according to the laws of the country in which it took place was also required to be validly recognised as a marriage by the EU country of the other contracting spouse: Kareem (Proxy marriages – EU law)  UKUT 24 (IAC).
However, in Awuku v SSHD  EWCA Civ 178, the courts finally put it to rest that proxy marriages are a matter of private international law and not EU law and that marital status and nationality are clearly distinguishable. Provided that a proxy marriage complies with the law of the land in which it is celebrated it will be recognised in England and Wales.
How does a person then prove that the proxy marriage complies with the law of the land in which it is celebrated? Some practitioners suggest a country expert with a detailed report, but others prefer to get an official document issued by Foreign Ministers and then provide an endorsement by their Ambassador in the UK. A letter from an Ambassador can negate the use of expert reports because the Ambassador is the representative of his or her Government in the UK. Furthermore, considering that embassies can be registered as a place where their citizens can freely get married, it is surprising that to-date many embassies have taken no action towards providing this confirmation service.
Very often it is our experience that the Home Office fails to grapple with issues of what constitutes a proxy marriage in some countries, for example, Senegal. Senegal is a Muslim country and about 95 percent of the population is Muslim. Many of its citizens are abroad and not everyone can return home to get married.
A proxy wedding or proxy marriage is a wedding in which one or both of the individuals being united are not physically present. Usually, being represented instead by other people and this would be the only option available to them.
Many Senegalese are unable to physically attend their wedding in Senegal for various reasons and this is due to material circumstances which are almost impossible to overcome. This might be caused by military service, criminal convictions, travel restrictions, immigration status or even religious and cultural reasons.
It is worth noting however that the legal requirement for an expert report of Ambassador’s letter is not enough on its own. The documents submitted alongside applications must clearly evidence companionship, emotional support and an abiding interest in each other‘s welfare and wellbeing from the beginning of their relationship.
In other claims, the Judge is asked to assess the durability of the relationship as opposed to the fact of marriage. In light of the numerous considerations set out above as to why proxy marriages are an important option for couples, it is essential that we remind ourselves there are no formal ways to truly assess marriages, as couples live in marriage in so many different ways and styles. As a result, in assessing whether there is sufficient evidence or suspicion by the state so as to interfere with EU law rights, decision-makers (both the Home Office and Judges) must not impose their own expectations of how a couple might conduct their relationship and should instead consider whether the evidence that has been presented is properly corroborative of the relationship claimed as directed in the Upper Tribunal decision in Goudey (subsisting marriage – evidence) Sudan  UKUT 00041 (IAC).