Halakhah zu Wajikra 25:50

And [it] is practiced in every place and at all times by males and females. And one who transgresses it and lies about measures of length, weight, or capacity has transgressed a negative commandment. But we do not administer lashes for it, because it is given to repayment. And (Ramban) [Rambam], may his memory be blessed, wrote (Mishneh Torah, Laws of Theft 7:8) that if one lied in measures even to a gentile that worships idolatry, he has transgressed a negative commandment and he is obligated to return [it]. And likewise is it forbidden to fool gentiles in calculations, as it is stated (Leviticus 25:50), "And calculate with his owner" - even if he is subjugated under your hand; all the more so towards a gentile that is not subjugated under your hand. And behold, it states (Deuteronomy 25:16), "For it is an abomination of God [...] anyone who does perversion" - in any case.