validateTaxIDSSN function

String? validateTaxIDSSN(
  1. String? value
)

Validates a Tax ID / Social Security Number (SSN). Returns null if valid, or an error message string if invalid.

Implementation

String? validateTaxIDSSN(String? value) {
  if (value == null || value.isEmpty) {
    return 'Please enter a tax ID or SSN';
  }
  // Basic SSN validation
  if (!RegExp(r'^\d{3}-\d{2}-\d{4}$').hasMatch(value)) {
    return 'Enter a valid SSN (XXX-XX-XXXX)';
  }
  return null;
}