Settling "Is salary source of funds?" means knowing which question is being asked. Money goes in with almost no questions and comes out with several, and that asymmetry catches most people at their first withdrawal. A casino is obliged to know who it is paying, where that person lives and where the money being staked came from, and it usually asks at the moment it is about to pay rather than when the account opened. Knowing which three checks exist, and what satisfies each, turns a stalled payout into an afternoon’s errand.
An answer that will not come has consequences worth knowing in advance. An account that cannot satisfy a source of funds request is usually frozen rather than closed, with the balance held until it can, and the deposits already made are normally returnable to their origin. That is the reason to deposit from an account in the same name from the start: every check further down the line reads more easily for a paper trail that began in the right place.
Source of funds is the third and the one people find intrusive. It asks where the money being gambled came from, and the answer is a document rather than a sentence: payslips, a tax return, a contract of sale, a statement showing the deposit arriving from a named employer. A salary is a perfectly ordinary answer and so is a pension, a redundancy payment or a house sale. What fails is an answer with no paper behind it, because the check is not asking whether the story is plausible.
Asked about this
How recent must proof of address be?
A bank statement, utility bill or council letter from the last three months, showing the name and address on the same page.
When does each payout check usually arrive?
Identity and address are often asked once; source of funds comes later, when totals through the account cross a threshold the operator does not publish.
Are online banking screenshots accepted as proof of address?
Usually, when they show the bank's name, the account holder and the address together; a screenshot showing only a balance fails.
Which document proves identity for a casino payout?
A passport, driving licence or national identity card with a photograph, full name and date of birth, photographed with all corners in frame and legible text.
What happens to the balance if an account is frozen?
The account is usually frozen rather than closed, the balance held until the source of funds is shown, and deposits are normally returnable to their origin.