If you've just signed up at an online casino or are attempting your first cashout and have been contacted by the casino to submit copies of documents like your ID or Passport as well as a utility bill or similar as proof of residential address for verification purposes, don't panic! This is perfectly normal and indicates that the online casino that you are dealing with is reputable and trustworthy and is interested in protecting both your and their own interests.
Online casinos that are governed by regulatory bodies are required to verify the age, identity and residential address of the player, before allowing them to play, although some only go through this process when payments are being made. Generally there is nothing underhanded going on and you don't have to be concerned about identity theft as long as you are definitely playing at a reputable online casino. So always make sure that you have researched the casino you would like to play at before actually doing so.
While some casinos do handle the document submission directly, there are also a number of agencies that handle this process on their behalf and once your documents are lodged with one of these agencies, then other casinos can access them with your consent, without bothering you again and again. This access is granted via a unique access code which is assigned to you as the player and you are then able to share it with the online casino requesting documents so that they can view them online. The time period for access is limited to that which you specify and you are able to block the casino once that time period has lapsed.
As a player these online agencies offer the advantage of having all necessary documents stored in a central place as well as the additional security benefit because your information will not be stored on the online casino servers. This also serves to reduce the risk of hacks that will cause your information to become public.
Whether you choose to submit your documents directly to the casino or to make use of an online agency as a storage point for these, always remember to investigate whoever you deal with thoroughly in advance to ensure your continued safety and security.