Much of "Is online casino legal?" is answered by the sign up form. Registering at an online casino takes a few minutes, and the form asks for more than a username. Name, date of birth, address, phone number and email are all used later, to check age, to match payments and to recover the account. Details typed carelessly at sign up are the most common reason for a verification problem weeks afterwards, so the form deserves a careful first look.
Casinos allow one account per person, and many extend the rule to a household, an address, a device or a payment method. A second account, even one opened by mistake after a forgotten password, can lead to both being closed and any winnings withheld. Recovering the original account through support is the safer route. Where several people in one home play, the terms say whether each can hold an account and what proof the casino wants.
Registration usually asks the player to confirm legal gambling age and to accept the terms, the privacy policy and sometimes marketing preferences. The age confirmation is checked later against a document, and an account opened by someone under age is closed with deposits returned and winnings void. The casino also checks where the player is connecting from, since a licence covers some places and excludes others, so playing while travelling can be blocked for a time.
Usernames are often permanent, so choosing one carefully at registration saves a support request later.
The casino checks where the player connects from, and a licence covering some places but not others can block play abroad for a while.
Exactly as on the identity document, including any middle names, because nicknames or shortened names create mismatches support fixes only after a delay.
Casinos allow one account per person, often per household, device or payment method, and a second account can get both closed and winnings withheld.
The email receives withdrawal notices and password resets, and the phone may act as a second login factor, so outdated contacts slow recovery.