Mapping international dialing codes to ISO 3166-1 alpha-2 country codes - https://keithgreer.dev/global-payments-sca-3d-secure-2

telephone-country-codes.php

/*
 * Usage: $calling_codes['GB'] will return "44", the UK's dialing code. 
 */

$calling_codes = [
  'BD' => '880',
  'BE' => '32',
  'BF' => '226',
  'BG' => '359',
  'BA' => '387',
  'BB' => '1246',
  'WF' => '681',
  'BL' => '590',
  'BM' => '1441',
  'BN' => '673',
  'BO' => '591',
  'BH' => '973',
  'BI' => '257',
  'BJ' => '229',
  'BT' => '975',
  'JM' => '1876',
  'BV' => '',
  'BW' => '267',
  'WS' => '685',
  'BQ' => '599',
  'BR' => '55',
  'BS' => '1242',
  'JE' => '441534',
  'BY' => '375',
  'BZ' => '501',
  'RU' => '7',
  'RW' => '250',
  'RS' => '381',
  'TL' => '670',
  'RE' => '262',
  'TM' => '993',
  'TJ' => '992',
  'RO' => '40',
  'TK' => '690',
  'GW' => '245',
  'GU' => '1671',
  'GT' => '502',
  'GS' => '',
  'GR' => '30',
  'GQ' => '240',
  'GP' => '590',
  'JP' => '81',
  'GY' => '592',
  'GG' => '441481',
  'GF' => '594',
  'GE' => '995',
  'GD' => '1473',
  'GB' => '44',
  'GA' => '241',
  'SV' => '503',
  'GN' => '224',
  'GM' => '220',
  'GL' => '299',
  'GI' => '350',
  'GH' => '233',
  'OM' => '968',
  'TN' => '216',
  'JO' => '962',
  'HR' => '385',
  'HT' => '509',
  'HU' => '36',
  'HK' => '852',
  'HN' => '504',
  'HM' => '',
  'VE' => '58',
  'PR' => '1939',
  'PS' => '970',
  'PW' => '680',
  'PT' => '351',
  'SJ' => '47',
  'PY' => '595',
  'IQ' => '964',
  'PA' => '507',
  'PF' => '689',
  'PG' => '675',
  'PE' => '51',
  'PK' => '92',
  'PH' => '63',
  'PN' => '870',
  'PL' => '48',
  'PM' => '508',
  'ZM' => '260',
  'EH' => '212',
  'EE' => '372',
  'EG' => '20',
  'ZA' => '27',
  'EC' => '593',
  'IT' => '39',
  'VN' => '84',
  'SB' => '677',
  'ET' => '251',
  'SO' => '252',
  'ZW' => '263',
  'SA' => '966',
  'ES' => '34',
  'ER' => '291',
  'ME' => '382',
  'MD' => '373',
  'MG' => '261',
  'MF' => '590',
  'MA' => '212',
  'MC' => '377',
  'UZ' => '998',
  'MM' => '95',
  'ML' => '223',
  'MO' => '853',
  'MN' => '976',
  'MH' => '692',
  'MK' => '389',
  'MU' => '230',
  'MT' => '356',
  'MW' => '265',
  'MV' => '960',
  'MQ' => '596',
  'MP' => '1670',
  'MS' => '1664',
  'MR' => '222',
  'IM' => '441624',
  'UG' => '256',
  'TZ' => '255',
  'MY' => '60',
  'MX' => '52',
  'IL' => '972',
  'FR' => '33',
  'IO' => '246',
  'SH' => '290',
  'FI' => '358',
  'FJ' => '679',
  'FK' => '500',
  'FM' => '691',
  'FO' => '298',
  'NI' => '505',
  'NL' => '31',
  'NO' => '47',
  'NA' => '264',
  'VU' => '678',
  'NC' => '687',
  'NE' => '227',
  'NF' => '672',
  'NG' => '234',
  'NZ' => '64',
  'NP' => '977',
  'NR' => '674',
  'NU' => '683',
  'CK' => '682',
  'XK' => '',
  'CI' => '225',
  'CH' => '41',
  'CO' => '57',
  'CN' => '86',
  'CM' => '237',
  'CL' => '56',
  'CC' => '61',
  'CA' => '1',
  'CG' => '242',
  'CF' => '236',
  'CD' => '243',
  'CZ' => '420',
  'CY' => '357',
  'CX' => '61',
  'CR' => '506',
  'CW' => '599',
  'CV' => '238',
  'CU' => '53',
  'SZ' => '268',
  'SY' => '963',
  'SX' => '599',
  'KG' => '996',
  'KE' => '254',
  'SS' => '211',
  'SR' => '597',
  'KI' => '686',
  'KH' => '855',
  'KN' => '1869',
  'KM' => '269',
  'ST' => '239',
  'SK' => '421',
  'KR' => '82',
  'SI' => '386',
  'KP' => '850',
  'KW' => '965',
  'SN' => '221',
  'SM' => '378',
  'SL' => '232',
  'SC' => '248',
  'KZ' => '7',
  'KY' => '1345',
  'SG' => '65',
  'SE' => '46',
  'SD' => '249',
  'DO' => '1809',
  'DM' => '1767',
  'DJ' => '253',
  'DK' => '45',
  'VG' => '1284',
  'DE' => '49',
  'YE' => '967',
  'DZ' => '213',
  'US' => '1',
  'UY' => '598',
  'YT' => '262',
  'UM' => '1',
  'LB' => '961',
  'LC' => '1758',
  'LA' => '856',
  'TV' => '688',
  'TW' => '886',
  'TT' => '1868',
  'TR' => '90',
  'LK' => '94',
  'LI' => '423',
  'LV' => '371',
  'TO' => '676',
  'LT' => '370',
  'LU' => '352',
  'LR' => '231',
  'LS' => '266',
  'TH' => '66',
  'TF' => '',
  'TG' => '228',
  'TD' => '235',
  'TC' => '1649',
  'LY' => '218',
  'VA' => '379',
  'VC' => '1784',
  'AE' => '971',
  'AD' => '376',
  'AG' => '1268',
  'AF' => '93',
  'AI' => '1264',
  'VI' => '1340',
  'IS' => '354',
  'IR' => '98',
  'AM' => '374',
  'AL' => '355',
  'AO' => '244',
  'AQ' => '',
  'AS' => '1684',
  'AR' => '54',
  'AU' => '61',
  'AT' => '43',
  'AW' => '297',
  'IN' => '91',
  'AX' => '35818',
  'AZ' => '994',
  'IE' => '353',
  'ID' => '62',
  'UA' => '380',
  'QA' => '974',
  'MZ' => '258',
];