First, I'd recommend you read something more about how we approach this topic, please.
There is something called the Fair Gambling Codex we seek to follow in order to stay transparent. Kindly take a few minutes to read this:
Common problematic areas in online gambling and how casinos should handle them
11. Player verification and duplicate accounts:
In a vast majority of casinos, players are only allowed to have one player account per casino. Opening more than one account is against the T&Cs, and duplicate accounts are generally closed after being discovered.
Most casinos only check for duplicate accounts as a part of the verification process, which is generally done when a player asks for a withdrawal. If a player wins something on one of their duplicate accounts, the winnings are generally annulled. In some cases, the initial deposits might be returned to the player if the casino believes the duplicate account was created by accident.
The casino's point of view
Casinos only allow players to create one account to protect themselves against bonus abusers. Opening multiple accounts and trying to claim the welcome bonus more than once is one of a small number of ways that players can use to gain an advantage over the casino, or at least make the casino's advantage smaller. This is why it makes sense that casinos protect themselves by closing duplicate accounts.
The player's point of view
Some players create multiple accounts on purpose (to abuse the welcome bonus), but it's sometimes the case that players simply forget they've already registered an account at a casino, and unknowingly create a new account.
Sometimes, players want to log in to their old account but don't remember their password. Instead of going through the 'forgotten password' procedure, they create a new account, perhaps not knowing that they are doing something that's against the rules.
Either way, we think that players shouldn't have to worry about accidentally creating duplicate accounts at the same casino.
Our position
We accept that it is the responsibility of players to make sure that they don't create multiple accounts at the same casino. Not because we think it's the right way to do it, but because it's the industry standard, and we cannot penalize all casinos that don't enforce the 'one account per player' rule the way we consider best. However, we believe and hope that checking for duplicate accounts during account creation will become the industry standard in the future and players will be better protected.
In the meantime, each case should be considered separately. If the casino finds out that a player has created five separate accounts and claimed the full bonus amount on each of them, it is likely that this is a bonus abuser, and the casino has every right to penalize them. On the other hand, if a casual player mistakenly creates two accounts and doesn't even claim the bonus, the casino shouldn't penalize them just because it has a rule that can be used against them.
Our recommendations for casinos
To prevent duplicate accounts, it is feasible and effective to check for duplicate accounts during the account creation process. We don't mean a full know your customer (KYC) procedure that would involve ID verification, but a quick check of personal detail combinations that would only be shared by two separate people in very rare exceptions, such as first name, surname and date of birth. If the casino doesn't require this information during the registration process, it should start doing so.
In most cases there will not be a match and the casino can let the player play, only triggering a full KYC procedure when the player submits their withdrawal request. However, if the casino does get a match, it is likely that the player already has an account. In these cases, notify the player and/or ask them to complete a KYC procedure to make sure that they don't already have an account.
If this is not technologically feasible, the casino shouldn't punish players who created a second account unknowingly and didn't intend to abuse the welcome bonus. If the player hasn’t caused you any harm, it's best to contact them and find an acceptable solution for both involved parties, such as keeping one account opened and closing the other one(s).
I appreciate your willingness to share what you feel is important. I believe we share the same optics when it comes to duplicate accounts.
I agree; it's not fair to void someone's winnings because another member of the household plays in the same casino using the same wifi, e.g.