What is the ruling on ta'dil al-arkan in prayer?

Ta'dil al-arkan means performing the pillars of the prayer properly, in their correct order, and completely. The term “tuma’nina,” which is used in a similar sense, refers to the state of being assured that the pillar being performed has been fulfilled as it should be. Ta'dil al-arkan is especially relevant in bowing (ruku‘), standing after bowing (qawma), prostration (sujud), and sitting between the two prostrations (jalsa). According to the strongest opinion in the Hanafi school, ta'dil al-arkan is wajib (obligatory) in these four positions. According to some other schools and also Imam Abu Yusuf from the Hanafis, ta'dil al-arkan is fard (an essential pillar). (Marghinani, al-Hidaya, 1/51; Ibn Abidin, Radd al-Muhtar, 1/464, 465, 472; Ibn Rushd, Bidayat al-Mujtahid, 1/143)

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu