It can be confusing trying to determine which countries are PCT contracting states, which aren’t, and which are considered other regional offices. Below are a couple of tables to help:
PCT Contracting States
| AE United Arab Emirates | IN India | NZ New Zealand |
| AG Antigua and Barbuda | JP Japan | OM Oman |
| *AL Albania | KM Union of the Comoros | PA Panama |
| AO Angola | KN Saint Kitts and Nevis | PE Peru |
| AU Australia | KP Democratic People’s republic of Korea | PG Papua New Guinea |
| *BA Bosnia and Herzegovina | KR Republic of Korea | PH Philippines |
| BB Barbados | LA Lao People’s Democratic Republic | QA Qatar |
| BH Bahrain | LC Saint Lucia | RS Serbia |
| BN Brunei Darussalam | LK Sri Lanka | SC Seychelles |
| BR Brazil | LR Liberia | SG Singapore |
| BZ Belize | LY Libyan Arab Jamahiriya | ST Sao Tome & Principe |
| CA Canada | MA Morocco | SV El Salvador |
| CL Chile | MD Republic of Moldova | SY Syrian Arab Republic |
| CN China | *ME Montenegro | TH Thailand |
| CO Colombia | MG Madagascar | TN Tunisia |
| CR Costa Rica | MN Mongolia | TT Trinidad and Tobago |
| CU Cuba | MX Mexico | UA Ukraine |
| DM Dominica | MY Malaysia | US United States of America |
| DO Dominican Republic | NG Nigeria | UZ Uzbekistan |
| DZ Algeria | NI Nicaragua | VC Saint Vincent and Grenadines |
| EC Ecuador | VN Viet Nam | |
| EG Egypt | ZA South Africa | |
| GD Grenada | * Extension of European patent possible | |
| GE Georgia | ||
| GT Guatemala | ||
| HN Honduras | ||
| ID Indonesia | ||
| IL Israel | ||
Other Regional Patent Offices
|
AP ARIPO Patent |
EA Eurasian Patent |
OA OAPI Patent (regional patent only) |
| BW Botswana | AM Armenia | BF Burkina Fasco |
| GH Ghana | AZ Azerbaijan | BJ Benin |
| GM Gambia | BY Belarus | CF Central African Republic |
| KE Kenya | KG Kyrgyzstan | CG Congo |
| LR Liberia | KZ Kazakhstan | CI Cote d’lvoire |
| LS Lesotho | RU Russian Federation | CM Cameroon |
| MW Malawi | TJ Tajikistan | GA Gabon |
| MZ Mozambique | TM Turkmenistan | GN Guinea |
| NA Namibia | GQ Equatorial Guinea | |
| RW Rwanda | ML Mali | |
| SD Sudan | MR Mauritania | |
| SL Sierra Leone | NE Niger | |
| SZ Swaziland | SN Senegal | |
| TZ United republic of Tanzania | TD Chad | |
| UG Uganda | TG Togo | |
| ZM Zambia | ||
| ZW Zimbabwe |
Countries that are not PCT Contracting States
| Afghanistan | Iran (Islamic Republic of) | Samoa |
| Andorra | Iraq | Saudi Arabia |
| Argentina | Jamaica | Solomon Islands |
| Bahamas | Jordan | Somalia |
| Bangladesh | Kiribati | South Sudan |
| Bhutan | Kuwait | Suriname |
| Bolivia | Lebanon | Timor-Leste |
| Burundi | Maldives | Tonga |
| Cambodia | Marshall Islands | Tuvalu |
| Cape Verde | Mauritius | Uruguay |
| Democratic Republic of Congo | Micronesia | Vanuatu |
| Djibouti | Myanmar | Venezuela |
| Eritrea | Nauru | Yemen |
| Ethiopia | Nepal | |
| Fiji | Pakistan | Taiwan (but not a country under UN – it is a province of China) |
| Guyana | Palau | |
| Haiti | Paraguay |