Islam produced creeds without ever producing a council that could impose one. There is no Nicaea in Islamic history, no assembly whose decisions bind the community, and no office empowered to convene one. Sunni creeds therefore acquire authority the slow way, by being taught, copied, commented on and found unobjectionable, and the creed of al-Tahawi is the clearest case of a text that won that kind of acceptance.
Abu Jafar al-Tahawi was an Egyptian jurist of the Hanafi school who died in 933. His creed is short, plain and almost entirely free of argument. It presents itself not as his own doctrine but as a statement of the belief of Abu Hanifa and his two principal companions, which locates it in a school rather than in a personality. It affirms the oneness of God, the uncreated Quran, the reality of the divine attributes without asking how, predestination, the intercession of the Prophet, and the obligation to obey lawful authority.
Its wide acceptance comes from what it does not do. It does not adjudicate the sharpest theological disputes of its century, it does not condemn named schools of Muslims, and it stays close to what the Sunni schools already held in common. Later scholars from more than one school wrote commentaries on it, which is the closest thing to ratification available in a tradition with no ratifying body.