Question:
In Ashkenazic tradition, if one takes upon himself a ta’anit yakhid, may he recite Avinu Malkenu as part of its observance?—or is it strictly a prayer for ta’aniyot tsibur?
Answer:
One can recite the Avinu Malkenu prayer even though he prays by himself.
Sources:
Eliyohu Rabah 584:5, Mateh Efrayim ibid 14. Teshuvas Rivevos Efrayim 2:165