| | I
| |
| 6996 | I AM Religious Movement | |
| 6996 | I AM, nai | |
| 0002 | I believe | |
| 7010 | Iconoclast | |
| 0002 | Idealist | |
| 2999 | Iglesia Ni Cristo | |
| 2499 | Immanuel Church of Australia | |
| 2499 | Immanuel Mission | |
| 2899 | In Spirit and in Truth Word of Bible | |
| 2051 | In the Name of the Lord Jesus Christ | |
| 6139 | Inca | |
| 6139 | Inca Sun Worshipper | |
| 0003 | Indefinite | |
| 2031 | Independent Baptist Churches | |
| 2899 | Independent Bible Church | |
| 2400 | Independent Charismatic | |
| 2400 | Independent Charismatic Church | |
| 2899 | Independent Christian Church | |
| 2899 | Independent Christian Household Church | |
| 6996 | Independent Church of Australia | |
| 2899 | Independent Church of Churches | |
| 2805 | Independent Church, nai | |
| 2805 | Independent Congregation | |
| 2807 | Independent Evangelical Churches | |
| 2331 | Independent Methodist | |
| 2899 | Independent Mission | |
| 2499 | Independent Pentecostal | |
| 2251 | Independent Presbyterian | |
| 2251 | Independent Presbyterian Church (Gold Coast) | |
| 2999 | Independent World Church | |
| 0002 | Independent, nai | |
| 0003 | Indeterminable | |
| 3011 | Indian Goddess Tradition | |
| 3011 | Indian Orthodox | |
| 3011 | Indian Religion | |
| 3011 | Indian, nai | |
| 7010 | Indifferent | |
| 0002 | Individual Faith | |
| 2806 | Indonesian Church | |
| 2171 | Indonesian Lutheran Church | |
| 7010 | Infidel | |
| 2911 | Infinite Way Study Centres | |
| 6999 | Inner Peace Movement | |
| 3011 | Integral Yoga Institute | |
| 2000 | Interdenominational | |
| 2999 | International Bible Students Association | |
| 2113 | International Church of Christ | |
| 6171 | International Council of Spiritualists Inc. | |
| 2311 | International Missionary Society of the Seventh Day | |
| 2911 | International New Thought Alliance | |
| 3011 | International Society for Krishna Consciousness | |
| 2071 | Irish Catholic | |
| 2251 | Irish Presbyterian | |
| 2899 | Irish Protestant | |
| 2252 | Irish Reformed Church of Africa | |
| 4011 | Islam | |
| 4011 | Islamic Monotheist | |
| 4011 | Ismailis (Seveners) | |
| 5011 | Israel | |
| 2111 | Israel Church of Christ | |
| 5011 | Israelita Yewis | |
| 5011 | Israelite | |
| 2402 | Italian Assembly of God Pentecostal | |
| 2806 | Italian Evangelical Christian Church | |
| 4011 | Ithna'asharis (Twelvers) | |