Carrier Connect uses the official format specifications for postal codes in the respective countries. The officially permitted formats are then converted, if necessary, into the formats expected by the carrier in order to determine routing results, service checks, and follow-up processes.
The following formats are required for the respective countries:
| Country | ISO code | Format (Z: Letter; 9: Number; not specified: postal code can be empty) |
| Afghanistan | AF | 9999 |
| Egypt | EG | 99999 |
| Aland | AX | not specified |
| Albania | AL | 9999 |
| Algeria | DZ | 99999 |
| United States Virgin Islands | VI | 99999-9999 |
| American Samoa | AS | ZZ 99999 |
| Andorra | AD | AD999 |
| Angola | AO | no postal code allowed |
| Anguilla | AI | no postal code allowed |
| Antarctica | AQ | not specified |
| Antigua and Barbuda | AG | nno postal code allowed |
| Equatorial Guinea | GQ | no postal code allowed |
| Argentina | AR | Z9999ZZZ |
| Armenia | AM | 9999 |
| Aruba | AW | no postal code allowed |
| Azerbaijan | AZ | ZZ 9999 or ZZ9999 |
| Ethiopia | ET | 9999 |
| Australia | AU | 9999 |
| Bahamas | BS | no postal code allowed |
| Bahrain | BH | 999 or 9999 |
| Peoples Rep. of Bangladesh | BD | 9999 |
| Barbados | BB | BB99999 |
| Belarus | BY | 999999 |
| Belgium | BE | 9999 |
| Belize | BZ | no postal code allowed |
| Benin | BJ | no postal code allowed |
| Bermuda | BM | ZZ 99 |
| Occupied Palestinian Territory | PS | not specified |
| Bhutan | BT | no postal code allowed |
| Venezuela | VE | 9999 |
| Bonaire, Saint Eustatius, Saba | BQ | not specified |
| Bosnia and Herzegovina | BA | 99999 |
| Botswana | BW | no postal code allowed |
| Bouvet Island | BV | not specified |
| Brazil | BR | 99999-999 |
| British Indian Ocean Territory | IO | Z9 9ZZ Z99 9ZZ ZZ9 9ZZ ZZ99 9ZZ Z9Z 9ZZ ZZ9Z 9ZZ |
| British Virgin Islands | VG | ZZ9999 |
| Brunei Darussalam | BN | ZZ9999 |
| Bulgara | BG | 9999 |
| Burkina Faso | BF | 99 or not specified |
| Burundi | BI | no postal code allowed |
| Ceuta | XC | not specified |
| Chile | CL | 999-9999 or 9999999 |
| Cook Islands | CK | 9999 |
| Costa Rica | CR | 99999 |
| Curacao | CW | not specified |
| Denmark | DK | 9999 |
| Dem. People's Rep. of Korea | KP | no postal code allowed |
| Democratic Republic Congo | CD | not specified |
| Federal Rep. of Germany | DE | 99999 |
| Dominica | DM | no postal code allowed |
| Dominican Republic | DO | 99999 |
| Dschibuti | DJ | no postal code allowed |
| Ecuador | EC | 999999 |
| El Salvador | SV | 9999 |
| Ivory Coast | CI | no postal code allowed |
| Eritrea | ER | no postal code allowed |
| Estonia | EE | 99999 |
| European Union | EU | not specified |
| Falkland Islands | FK | ZZZZ 9ZZ |
| Faröer | FO | ZZ999 |
| Republic of Fiji | FJ | no postal code allowed |
| Finland | FI | 99999 |
| Federated States of Micronesia | FM | ZZ 99999 |
| France | FR | 99999 |
| French Polynesia | PF | 99999 |
| French Southern Territories | TF | 99999 |
| French-Guayana | GF | 99999 |
| Gabon | GA | no postal code allowed |
| Gambia | GM | no postal code allowed |
| Georgien | GE | 9999 |
| Ghana | GH | no postal code allowed |
| Gibraltar | GI | not specified |
| Grenada | GD | no postal code allowed |
| Greece | GR | (999 99)|(99999) |
| Greenland | GL | 9999 |
| Guadeloupe | GP | 99999 |
| Guam | GU | ZZ 99999 or 99999 |
| Guatemala | GT | 99999 |
| Guernsey | GG | not specified |
| Guinea | GN | no postal code allowed |
| Guinea-Bissau | GW | 9999 |
| Guyana | GY | no postal code allowed |
| Haiti | HT | ZZ9999 |
| Heard Is. & McDonald Islands | HM | 9999 |
| Vatican City | VA | 99999 |
| High Seas | QP | not specified |
| Honduras | HN | ZZ9999 or ZZ99999 |
| Hong Kong, China | HK | not specified |
| India | IN | 999999 |
| Indonesia | ID | 99999 |
| Iraq | IQ | 99999 |
| Iran | IR | 9999999999 |
| Ireland | IE | not specified |
| Iceland | IS | 999 |
| Isle of Man | IM | not specified |
| Israel | IL | 99999 or 9999999 |
| Italia | IT | 99999 |
| Jamaica | JM | no postal code allowed |
| Japan | JP | 999-9999 |
| Jersey | JE | not specified |
| Jordan | JO | 99999 |
| Cayman Islands | KY | ZZ9-9999 |
| Cambodia | KH | (99999)|(999999) |
| Cameroon | CM | no postal code allowed |
| Canada | CA | Z9Z 9Z9 |
| Cape Verde | CV | 9999 |
| Kazakhstan | KZ | 999999 |
| Quatar | QA | no postal code allowed |
| Kenya | KE | 99999 |
| Kyrgyzstan | KG | 999999 |
| Republic of Kiribati | KI | no postal code allowed |
| US Minor Outlying Islands | UM | 99999-9999 |
| Cocos Islands | CC | 9999 |
| Colombia | CO | 999999 |
| Comoros | KM | no postal code allowed |
| Congo | CG | no postal code allowed |
| Kosovo | XK | not specified |
| Croatia | HR | 99999 or HR99999 or HR-99999 |
| Cuba | CU | 99999 |
| Kuwait | KW | 99999 |
| Laos | LA | 99999 |
| Lesotho | LS | 999 |
| Latvia | LV | LV-9999 or 9999 |
| Lebanon | LB | 9999 9999 or 9999 |
| Liberia | LR | 9999 |
| Libya | LY | not specified |
| Liechtenstein | LI | 9999 |
| Lithuania | LT | LT-99999 or 99999 |
| Luxembourg | LU | 9999 |
| Macau, China | MO | no postal code allowed |
| Madagascar | MG | 999 |
| Malawi | MW | no postal code allowed |
| Malaysia | MY | 99999 |
| Republic of Maldives | MV | 99999 |
| Mali | ML | no postal code allowed |
| Malta | MT | ZZZ 9999 |
| Marocco | MA | 99999 |
| Marshall Islands | MH | ZZ99999 |
| Martinique | MQ | 99999 |
| Mauretania | MR | no postal code allowed |
| Mauritius | MU | not specified |
| Mayotte | YT | 99999 |
| Melilla | XL | not specified |
| Mexico | MX | 99999 |
| Monaco | MC | not specified |
| Mongolian People's Republic | MN | 99999 |
| Montenegro | ME | 99999 |
| Montserrat | MS | no postal code allowed |
| Mozambique | MZ | 9999 |
| Union of Myanmar | MM | 99999 |
| Republic of Naur | NR | no postal code allowed |
| Kingdom of Nepal | NP | 99999 |
| New Caledonia | NC | 99999 |
| New Zealand | NZ | 9999 |
| Nicaragua | NI | 999-999-9 or 99999 |
| The Netherlands | NL | 9999 ZZ or 9999ZZ |
| Niger | NE | 9999 |
| Fereral Republic of Nigeria | NG | 999999 |
| Niue | NU | 9999 |
| Northern Mariana Islands | MP | ZZ99999 |
| The F.Y.R. of Macedonia | MK | 9999 |
| Norfolk Island | NF | 9999 |
| Norway | NO | 9999 |
| Sultanate of Oman | OM | 999 |
| Austria | AT | 9999 |
| Pakistan | PK | 99999 |
| Palau | PW | ZZ99999 |
| Panama | PA | no postal code allowed |
| Papua-Neuguinea | PG | 999 |
| Paraguay | PY | 9999 (obsolete) 999999 |
| Peru | PE | 99999 |
| Philippinen | PH | 9999 |
| Pitcairn Islands | PN | ZZZZ 9ZZ |
| Bolivia | BO | no postal code allowed |
| Poland | PL | 99-999 |
| Portugal | PT | 9999-999 |
| Puerto Rico | PR | 99999 or PR99999 |
| Réunion | RE | 99999 |
| Republic of Yemen | YE | no postal code allowed |
| Republic of Korea | KR | 999-999 or 99999 |
| Republic of Moldova | MD | MD-9999 or MD9999 or 9999 |
| Republic of Namibia | NA | no postal code allowed |
| Republik of South Africa | ZA | 9999 |
| Ruanda | RW | no postal code allowed |
| Romania | RO | 999999 |
| Russian Federation | RU | 999999 |
| State of Solomon Islands | SB | no postal code allowed |
| Zambia | ZM | 99999 |
| Samoa | WS | no postal code allowed |
| San Marino | SM | 99999 |
| São Tomé & Príncipe | ST | no postal code allowed |
| Saudi-Arabia | SA | 99999 |
| Sweden | SE | 999 99 or ZZ-999 99 |
| Switzerland | CH | 9999 |
| Senegal | SN | 99999 |
| Serbia | RS | 99999 |
| Serbia and Montenegro | CS | not specified |
| Seychelles | SC | no postal code allowed |
| Sierra Leone | SL | no postal code allowed |
| Zimbabwe | ZW | no postal code allowed |
| Republic of Singapore | SG | 999999 |
| Slovak Republic | SK | 999 99 |
| Slowenia | SI | SI-9999 or 9999 |
| Somalia | SO | not specified |
| Spain | ES | 99999 |
| Spitsbergen and Jan Mayen | SJ | not specified |
| Dem.Soc.Rep. of Sri Lanka | LK | 99999 |
| St. Barthélemy | BL | 99999 |
| St. Helena | SH | ZZZZ 9ZZ |
| St. Kitts und Nevis | KN | nno postal code allowed |
| St. Lucia | LC | no postal code allowed |
| Sint Maarten | SX | 99999 |
| St. Pierre and Miquelon | PM | 99999 |
| St. Vincent & the Grenadines | VC | no postal code allowed |
| Sudan | SD | 99999 |
| S. Georgia & S. Sandwich Islands | GS | ZZZZ 9ZZ |
| South Sudan | SS | not specified |
| Suriname | SR | no postal code allowed |
| Swaziland | SZ | Z999 |
| Syrian Arab Republic | SY | not specified |
| Tajikistan | TJ | 999999 |
| Taiwan | TW | 999 or 999 99 or 99999 or 999 999 or 999999 |
| United Republic of Tanzania | TZ | not specified |
| Kingdom of Thailand | TH | 99999 |
| Timor-Leste | TL | no postal code allowed |
| Togo | TG | no postal code allowed |
| Tokelau | TK | 9999 |
| Tonga | TO | no postal code allowed |
| Trinidad ans Tobago | TT | not specified |
| Tschad | TD | no postal code allowed |
| Czech Republic | CZ | 999 99 |
| Tunisia | TN | 9999 |
| Turkey | TR | 99999 |
| Turkmenistan | TM | 999999 |
| Turks and Caicos Islands | TC | ZZZZ 9ZZ |
| Tuvalu | TV | no postal code allowed |
| Uganda | UG | no postal code allowed |
| Ukraine | UA | 99999 |
| Hungary | HU | 9999 |
| Uruguay | UY | 99999 |
| Uzbekistan | UZ | 999999 |
| Vanuatu | VU | no postal code allowed |
| Vereinigte Arabische Emirate | AE | no postal code allowed |
| United States Of America | US | 99999 |
| United Kingdom | GB | Z9 9ZZ Z99 9ZZ ZZ9 9ZZ ZZ99 9ZZ Z9Z 9ZZ ZZ9Z 9ZZ |
| Vietnam | VN | 99999 999999 (obsolete) |
| People's Republic of China | CN | 999999 |
| Wallis and Futuna Islands | WF | 99999 |
| Christmas Island | CX | 9999 |
| Western Sahara | EH | not specified |
| Central African Republic | CF | no postal code allowed |
| Cyprus | CY | 9999 |