If we recite multiple surahs in one rakat do we have to recite bismillah for each surah? some say yes some say no?
There is difference of opinion on whether Bismillah is a proper part of each surah or just recited for blessing. Based on this some say that it should be recited before each surah while some disagree. We can not tell you which opinion to follow.
Refer to the second half of this answer: https://islam.stackexchange.com/a/36470/20218