Unverified50% confidenceFactExact time
Bank card numbers follow the Luhn algorithm checksum, with Visa starting with 4 and Mastercard starting with 51–55
1
Sources
50%
Confidence
Long-term
Relevance
8/8/2026
First Seen
Sources
DataBlur：实时模糊屏幕敏感数据的本地化隐私保护工具
Related Claims
UnverifiedCredit card numbers have fixed prefixes by card network: Visa starts with 4, and Mastercard starts with 51–5577% similarUnverifiedThe last digit of almost all credit card and debit card numbers is a Luhn check digit, which allows card number validity to be determined through mathematical calculation without accessing bank databases68% similarUnverifiedChinese domestic bank cards (including Visa/Mastercard co-branded cards) frequently encounter payment failures and risk-control blocks when being bound to overseas AI platforms.60% similar
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