Is it permitted to tutor someone during Chol Hamoed for payment?
Answer
Yes. If the tutoring involves Torah subjects, it is certainly permitted to teach and receive payment during Chol Hamoed, as teaching Torah is itself a mitzvah and is included in the activities that may be performed on Chol Hamoed and by matters that are permitted to be done on Chol Hamoed, and are done for the sake of the Moeid, and is not considered a Melacha, payment is permitted. Indeed, based on this, musicians work for pay on Chol Hamoed.
Furthermore, even if the tutoring involves secular studies, it may be permitted when there is a need related to the mo’ed. For example, if the student is preparing for an upcoming examination or must complete coursework during Chol Hamoed, one may tutor the student and receive payment for doing so.
Sources:
See Michaber 542:1; 545:1; M”B 541:1; Biur Halacha 541:1 Afilu [that by Ochel Nefesh may collect money] and 544:1 “Tzarchei Rabim” [may collect money]; Kol Bo 60, brought in Beis Yosef 541 regarding all Melacha that is Tzorech Hamoed; Beir Moshe 7:14 regarding baby sitter; Moadim Uzemanim 7:155 regarding babysitter; Avnei Yashpei 7:88; Avnei Darech 7:91; Chol Hamoed Kehilchaso 9:1-4 regarding Tzorech Mitzvah or if not a Melacha at all