Your exchange of marriage vows before two witnesses is what creates your legal marriage. The paperwork is generally completed and lodged by your celebrant with the state authority within the prescribed period, and all is well! Brides who wish to change their surname on their drivers licence and/or passport are required to produce the registered 'full' marriage certificate as proof of their name change. This document is obtained by applying to the Registrar of Marriages in the state in which you were married.
No matter where you reside, you can generally make this application online with little if any pain.
If couples feel they have no need to obtain this 'registered' marriage certificate, they can avoid paying the prescribed fee involved. However I suggest that all marrying couples part with the small sum involved and make application for a copy of their registered marriage certificate...why do I recommend this? (Do I get a 'kickback'...no way!)
I have received emails or phone calls from distressed couples (not many, but enough) to say they applied for this document, only to be told that it was never lodged, and there is NO record of their marriage. On all three occasions that come to mind, the paperwork was delivered to the Registrar of Marriages within 48 hours of the marriage (well within the 14 days prescribed in the Marriage Act 1961). An error within the government office has, in each instance, resulted in a 'mis-filing' or omission of some description, the end result of which is that the marriage was never 'entered', 'processed' or given a registration number.
This is not a scare tactic or an exercise in 'finger pointing' or 'naming and shaming'; let's face it, mistakes do occur, in all facets of life. (Three such incidents in almost twenty years is not a major system failure by any standard.) The ONLY way you can be certain that your marriage has been registered is to make an application for a registered copy of your Marriage Certificate.
It is my practice to hand deliver the paperwork to the Registrar of Marriages within two business days as I prefer not to assume that even the postal system is without glitches. For some of my colleagues this is not practical, and there is a need to trust the mail. Some forward thinking states have 'online' lodgement for celebrants, and I live for that day to arrive in Tasmania.
In the meantime, my method of hand delivery at least gives me the peace of mind that I have duly completed my duty to each couple, and their marriage has the best chance of being registered accurately and in a timely manner.