I've never heard of such a thing. How would a bank know your post retirement income and why would they check? I've had credit cards since 1998 and retired 10.5 years and had about 5 cards approved since. I'm on a government pension and topped up by a part age pension so not a big income.
I'm about to apply for my next card for maximum sign on bonus points so probable won't get it approved after putting a hex on myself by writing this!
The banks do know how much you earn, eg/ie, BankSA do list the category of income, "government payments" and the pension that is entered fortnightly into my mums account.
They also know who pays you.
Its more so if a bank officer is tasked, to do checking, or tracing, that they will call to confirm info.
I watch it like a warhawk.
There are a lot of things the bank knows, and you are lucky you havent had to do the FACTA report, "we notice that you have some information on your account from an overseas source"... just because I used an overseas passport (at that time) to open said account, then they want to know source of income, what is your job, who you are employed by, ... or was it KYC (know your customer), because the bank has to keep records re AML/CTF data keeping or reporting etc, ...
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It comes under Source of Funds/Source of Wealth.