On Tisha B’Av the tefilla of Nachaim is added into Bonav Yerushalavim the tefilla of Nachaim is added into Bonay Yerushalayim and Anaynu is added into Shomaya Tefilla. Our minhag is to say these Tefillos only at Mincha. (ShA – Rama)
If forgotten, you do not have to repeat the Shemoneh Esray. If you remembered Nachaim before ending R’tzay, add it into R’tzay just before “…V’sechezenna…”. Then complete the beracha normally without the special ending of “Boruch menachem Tzion…” (SHA – MB2)
