Accounting Format (Negative in Parentheses) Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching accounting format (negative in parentheses), 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

// Accounting Format (Negative in Parentheses)
// ReDoS-safe | RegexVault — Finance > Currency & Money

package validation

import "regexp"

var accountingFormatNegativeInParenthesesRe = regexp.MustCompile(`^(?:\((?:(?:[1-9][0-9]*(?:,[0-9]{3})*)|0)(?:\.[0-9]{1,2})?\)|(?:(?:[1-9][0-9]*(?:,[0-9]{3})*)|0)(?:\.[0-9]{1,2})?)$`)

func ValidateAccountingFormatNegativeInParentheses(s string) bool {
    return accountingFormatNegativeInParenthesesRe.MatchString(s)
}

// Example
// fmt.Println(ValidateAccountingFormatNegativeInParentheses("1,234.56")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Currency & Money 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

Standard accounting/financial statement format. Parentheses denote debit or loss depending on context. Strip parentheses and negate when converting to numeric type for calculation.