When I applied for an Agricultural Bank of China credit card, I filled in 50,000 when I filled in the overdraft limit, but my average annual income was only 30,000.

It will definitely take into account your income level. Your limit was filled in too high, or you could have filled in your income higher at that time. As for whether the bank can apply for a low-limit card for you now, it depends on whether you selected "if the applied limit is not approved, do you agree to apply for a card with a lower limit" on the card application form at that time.

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