The United Pentecostal Church International (UPCI) is a Pentecostal denomination formed by a 1945 merger of the Pentecostal Church, Incorporated, and the Pentecostal Assemblies of Jesus Christ. The UPCI is headquartered in Hazelwood, Missouri
It dates back to October 1916, when a large group of ministers withdrew from the Assemblies of God over the doctrinal issues of the oneness of God and water baptism in the name of Jesus Christ. Specifically, the UPCI holds most of the beliefs of the Holiness-Pentecostal movement, including the Pentecostal view that speaking in tongues is the initial sign of receiving the Holy Spirit, but rejects the doctrine of the Trinity (see Oneness_Pentecostals) and the traditional Trinitarian formula in water baptism.