European Debit Card Number

Detects European debit and credit card numbers for Visa, Mastercard, and American Express networks. The pattern matches 13- to 16-digit card numbers based on the leading digits assigned to each network by the ISO/IEC 7812 standard. This is commonly used for PCI-DSS compliance scanning across EU-regulated financial data.

Type: regex
Engine: universal
Confidence: high
Confidence justification: Card numbers have well-defined prefix ranges (4 for Visa, 51-55 for Mastercard, 34/37 for Amex) and fixed lengths, giving this pattern strong structural precision. Luhn validation as a post-match step further reduces false positives.
Detection quality: Verified
Jurisdictions: eu
Regulations: GDPR
Frameworks: ISO 27001, ISO 27701, PCI-DSS, SOC 2
Data categories: financial, pii
Scope: narrow
Risk rating: 9
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Unsupported

Pattern

\b(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13})\b

Corroborative evidence keywords

card number, debit card, credit card, card no, CVV, expiry, CC, visa, mastercard, amex, american express, discover, jcb, diners club, CVC, security code, card verification, 3 digit, 4 digit code, expiration (+5 more)

Proximity: 300 characters

Should match

4111111111111111 — Valid Visa test card number (16 digits)
5500000000000004 — Valid Mastercard test card number
340000000000009 — Valid American Express test card number (15 digits)

Should not match

1234567890123456 — 16-digit number that does not match any known card prefix
411111111111 — Too few digits to be a valid Visa card number
6011000000000004 — Discover card prefix, not covered by this EU-focused pattern

Known false positives

Random 16-digit numbers that happen to start with a valid card prefix (e.g. serial numbers, tracking codes) Mitigation: Apply Luhn checksum validation on matched values. Require corroborative evidence keywords such as 'card number' or 'CVV' within proximity.