Answered by Ustadh Tabraze Azam
Question:As salaamu alaykum,
If someone has been reading a letter of the Fatiha incorrectly for some time but is not sure how long does he need to repeat all his past prayers?
Answer: Wa alaikum assalam wa rahmatullah,
I pray this finds you in the best of health and faith, insha’Allah.
No, you do not need to make up any prayers.
And Allah knows best.
Checked & Approved by Shaykh Faraz Rabbani