// code is A.I generated, use with care
function isValidTaxId(taxId, country) {
  let regex;

  switch (country) {
    case 'US':
      // US EIN format: 00-0000000
      regex = /^(\d{2}-\d{7})$/;
      break;
    case 'DE':
      // German VAT format: DE000000000
      regex = /^(DE\d{9})$/;
      break;
    case 'AU':
      // Australian Business Number (AU ABN): 12345678912
      regex = /^(\d{11})$/;
      break;
    case 'BR':
      // Brazilian CNPJ number: 01.234.456/5432-10
      regex = /^(\d{2}\.\d{3}\.\d{3}\/\d{4}-\d{2})$/;
      break;
    case 'CA':
      // Canadian BN: 123456789
      regex = /^(\d{9})$/;
      break;
    case 'CL':
      // Chilean TIN: 12.345.678-K
      regex = /^(\d{2}\.\d{3}\.\d{3}-[A-Z])$/;
      break;
    case 'CN':
      // Chinese tax ID: 123456789012345678
      regex = /^(\d{18})$/;
      break;
    case 'EC':
      // Ecuadorian RUC number: 1234567890001
      regex = /^(\d{13})$/;
      break;
    case 'EG':
      // Egyptian Tax Identification Number: 123456789
      regex = /^(\d{9})$/;
      break;
    case 'HK':
      // Hong Kong BR number: 12345678
      regex = /^(\d{8})$/;
      break;
    case 'IN':
      // Indian GST number: 12ABCDE3456FGZH
      regex = /^(\d{2}[A-Z]{5}\d{4}[A-Z]{1}\d{1}[A-Z]{1}\d{1})$/;
      break;
    case 'JP':
      // Japanese Corporate Number (*Hōjin Bangō*): 1234567891234
      regex = /^(\d{13})$/;
      break;
    case 'LT':
      // Lithuanian VAT: LT123456789
      regex = /^(LT\d{9})$/;
      break;
    case 'LU':
      // Luxembourg VAT: LU12345678
      regex = /^(LU\d{8})$/;
      break;
    case 'LV':
      // Latvian VAT: LV12345678901
      regex = /^(LV\d{11})$/;
      break;
    case 'MT':
      // Maltese VAT: MT12345678
      regex = /^(MT\d{8})$/;
      break;
    case 'NL':
      // Dutch VAT: NL123456789B01
      regex = /^(NL\d{9}B\d{2})$/;
      break;
    case 'PL':
      // Polish VAT: PL1234567890
      regex = /^(PL\d{10})$/;
      break;
    case 'PT':
      // Portuguese VAT: PT123456789
      regex = /^(PT\d{9})$/;
      break;
    case 'RO':
      // Romanian VAT: RO1234567890
      regex = /^(RO\d{10})$/;
      break;
    case 'SE':
      // Swedish VAT: SE123456789001
      regex = /^(SE\d{12})$/;
      break;
    case 'SI':
      // Slovenian VAT: SI12345678
      regex = /^(SI\d{8})$/;
      break;
    case 'SK':
      // Slovak VAT: SK1234567890
      regex = /^(SK\d{10})$/;
      break;
    case 'TR':
      // Turkish VAT: TR1234567890
      regex = /^(TR\d{10})$/;
      break;
    case 'TW':
      // Taiwanese VAT: TW12345678
      regex = /^(TW\d{8})$/;
      break;
    case 'UA':
      // Ukrainian VAT: UA1234567890
      regex = /^(UA\d{10})$/;
      break;
    case 'UK':
      // UK VAT: GB123456789
      regex = /^(GB\d{9})$/;
      break;
    case 'VN':
      // Vietnamese VAT: VN1234567890A1
      regex = /^(VN\d{10}[A-Z]\d)$/;
      break;
  case 'AD':
      // Andorran NRT number: A-123456-Z
      regex = /^(A-\d{6}-[A-Z])$/;
      break;
    case 'AR':
      // Argentinian tax ID number: 12-3456789-01
      regex = /^(\d{2}-\d{8}-\d{2})$/;
      break;
    case 'BE':
      // Belgian VAT: BE0123456789
      regex = /^(BE\d{10})$/;
      break;
    case 'BO':
      // Bolivian tax ID: 123456789
      regex = /^(\d{9})$/;
      break;
    case 'BG':
      // Bulgarian VAT: BG123456789
      regex = /^(BG\d{9})$/;
      break;
    case 'CL':
      // Chilean TIN: 12.345.678-K
      regex = /^(\d{2}\.\d{3}\.\d{3}-[A-Z])$/;
      break;
    case 'CO':
      // Colombian NIT number: 123.456.789-0
      regex = /^(\d{3}\.\d{3}\.\d{3}-\d)$/;
      break;
    case 'CR':
      // Costa Rican tax ID: 1-234-567890
      regex = /^(\d-\d{3}-\d{6})$/;
      break;
    case 'HR':
      // Croatian VAT: HR12345678912
      regex = /^(HR\d{11})$/;
      break;
    case 'CY':
      // Cypriot VAT: CY12345678Z
      regex = /^(CY\d{8}[A-Z])$/;
      break;
    case 'CZ':
      // Czech VAT: CZ1234567890
      regex = /^(CZ\d{10})$/;
      break;
    case 'DK':
      // Danish VAT: DK12345678
      regex = /^(DK\d{8})$/;
      break;
    case 'DO':
      // Dominican RCN number: 123-4567890-1
      regex = /^(\d{3}-\d{7}-\d)$/;
      break;
    case 'SV':
      // El Salvadorian NIT number: 1234-567890-123-4
      regex = /^(\d{4}-\d{6}-\d{3}-\d)$/;
      break;
    case 'EE':
      // Estonian VAT: EE123456789
      regex = /^(EE\d{9})$/;
      break;
    case 'FI':
      // Finnish VAT: FI12345678
      regex = /^(FI\d{8})$/;
      break;
    case 'FR':
      // French VAT: FRAB123456789
      regex = /^(FR[A-Z]{2}\d{9})$/;
      break;
    case 'GE':
      // Georgian VAT: 123456789
      regex = /^(\d{9})$/;
      break;
    case 'GR':
      // Greek VAT: EL123456789
      regex = /^(EL\d{9})$/;
      break;
    case 'HU':
      // Hungarian VAT: HU12345678
      regex = /^(HU\d{8})$/;
      break;
    case 'IS':
      // Icelandic VAT: 123456
      regex = /^(\d{6})$/;
      break;
    case 'ID':
      // Indonesian NPWP number: 12.345.678.9-012.345
      regex = /^(\d{2}\.\d{3}\.\d{3}\.\d-\d{3}\.\d{3})$/;
      break;
    case 'IE':
      // Irish VAT: IE1234567AB
      regex = /^(IE\d{7}[A-Z]{1,2})$/;
      break;
    case 'IT':
      // Italian VAT: IT12345678912
      regex = /^(IT\d{11})$/;
      break;
    case 'LV':
      // Latvian VAT: LV12345678901
      regex = /^(LV\d{11})$/;
      break;
    case 'LT':
      // Lithuanian VAT: LT123456789
      regex = /^(LT\d{9})$/;
      break;
    case 'LU':
      // Luxembourg VAT: LU12345678
      regex = /^(LU\d{8})$/;
      break;
    case 'MY':
      // Malaysian Service Tax: 12345678912
      regex = /^(\d{11})$/;
      break;
    case 'MT':
      // Maltese VAT: MT12345678
      regex = /^(MT\d{8})$/;
      break;
    case 'MX':
      // Mexican VAT: MX1234567890
      regex = /^(MX\d{10})$/;
      break;
    case 'NL':
      // Dutch VAT: NL123456789B01
      regex = /^(NL\d{9}B\d{2})$/;
      break;
    case 'NZ':
      // New Zealand GST: 12345678912
      regex = /^(\d{11})$/;
      break;
    case 'NO':
      // Norwegian VAT: NO123456789
      regex = /^(NO\d{9})$/;
      break;
    case 'PL':
      // Polish VAT: PL1234567890
      regex = /^(PL\d{10})$/;
      break;
    case 'PT':
      // Portuguese VAT: PT123456789
      regex = /^(PT\d{9})$/;
      break;
    case 'RO':
      // Romanian VAT: RO1234567890
      regex = /^(RO\d{10})$/;
      break;
    case 'SA':
      // Saudi Arabian VAT: 1234567890
      regex = /^(\d{10})$/;
      break;
    case 'SG':
      // Singaporean GST: 12345678912
      regex = /^(\d{11})$/;
      break;
    case 'SK':
      // Slovak VAT: SK1234567890
      regex = /^(SK\d{10})$/;
      break;
    case 'SI':
      // Slovenian VAT: SI12345678
      regex = /^(SI\d{8})$/;
      break;
    case 'ZA':
      // South African VAT: 1234567890
      regex = /^(\d{10})$/;
      break;
    case 'KR':
      // South Korean VAT: 1234567890
      regex = /^(\d{10})$/;
      break;
    case 'ES':
      // Spanish VAT: ES12345678Z
      regex = /^(ES\d{8}[A-Z])$/;
      break;
    case 'SE':
      // Swedish VAT: SE123456789001
      regex = /^(SE\d{12})$/;
      break;
    case 'CH':
      // Swiss VAT: CHE123456789
      regex = /^(CHE\d{9})$/;
      break;
    case 'TH':
      // Thai VAT: 1234567890123
      regex = /^(\d{13})$/;
      break;
    case 'TR':
      // Turkish VAT: TR1234567890
      regex = /^(TR\d{10})$/;
      break;
    case 'AE':
      // UAE VAT: 123456789012345
      regex = /^(\d{15})$/;
      break;    
    default:
      return false;
  }

  return regex.test(taxId);
}