Discover Card Number Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching discover card number, ported and verified for Go. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// Discover Card Number
// ReDoS-safe | RegexVault — Finance > Card Numbers

package validation

import "regexp"

var discoverCardNumberRe = regexp.MustCompile(`^(?:6011[0-9]{12}|64[4-9][0-9]{13}|65[0-9]{14}|622(?:1(?:2[6-9]|[3-9][0-9])|[2-8][0-9]{2}|9(?:[01][0-9]|2[0-5]))[0-9]{10})$`)

func ValidateDiscoverCardNumber(s string) bool {
    return discoverCardNumberRe.MatchString(s)
}

// Example
// fmt.Println(ValidateDiscoverCardNumber("6011111111111117")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Card Numbers category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Discover has multiple BIN ranges. The 622126-622925 range (UnionPay cobranded) was added later. Some validators miss the 644-649 and UnionPay ranges.