Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we commend your pursuit of knowledge and your eagerness to seek what is lawful and avoid what is not. We earnestly implore Allah to bless your efforts in this honorable way.
It is noteworthy that Islam pays great attention to marriage, taking all measures to protect the family life and relations between the spouses against any suspicion or difficulty that may arise in the future. Therefore, marriages must be done in complete compliance with the laws of the land one is living in, for marriage entails certain obligations and duties that cannot be enforced except through legalizing it.
Responding to your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto,Ontario, Canada, states:
Marriages, properly speaking, must be done in complete compliance with the laws of the land one is living in, for marriage entails certain obligations and duties that cannot be enforced except through legalizing it. So I insist that every Muslim who is desirous of getting married should do so in compliance with the laws of the country he or she is living in. Therefore, it is extremely important for us to ensure that marriages are properly registered and legally documented, instead of merely formalized through a verbal nikah ceremony alone. This is so because of the fact that failure to comply with the laws of the land may likely entail grave and incalculable harm for the parties involved. Islam orders us to guard ourselves against all possible harm or injury involving ourselves and others.
By failing to register marriages, the parties cannot have recourse to legal channels to get their rights and responsibilities enforced. Islam does not allow for anarchy; the wisdom of Islamic jurists have told us that some laws are better than no laws. In countries where Islamic laws are not enforced, we are not allowed to take the laws in our own hands, for there are no authorities to enforce the Islamic laws; so we must abide by the existing laws. In fact, especially in regards to marriage in particular, we have every facility here that allows us to get married simultaneously legally and Islamically.
Therefore, I must insist that the proper procedure is to get the proper license for marriage, which can be signed by the imam or marriage officer who is authorized to perform marriages. This is the surest, safest, and proper procedure, which is at once in perfect agreement with the teachings of Islam as well as the laws of the land we are living in.
Finally, as Muslims living here we must never fall into the temptation of breaking the laws of the land which we have chosen to be the citizens of.
Almighty Allah knows best.
Excerpted, with slight modifications, from: www.islam.ca