Is the issur of “lo salin paulas scar itcha ad boker” also shayach by a goyish worker?
Answer:
No, the prohibition applies only to Jewish workers, as the Mishnah states (Bava Metzia 111).
However, some explain that according to the Rambam, the positive mitzvah of paying a worker on time applies even to a non-Jewish worker. It certainly applies to those non-Jews who are considered gerei toshav (as the Mishnah writes; see Rambam, Sechirus Chap. 11).
In Sefer Ha-Mitzvos, the Rambam writes that the positive mitzvah applies even to non-Jews, and the Chinuch copies this is mitzvah 230. The sefer Kav Yashar writes that one who does not pay a non-Jew on time is punished severely.
Therefore, one should certainly be sure to pay even a non-Jewish worker on time.