Q: When I asked my dentist about payment, he said, “We’ll bill you.” May I delay payment until I receive the bill? When I receive the bill, must I pay it immediately?

A: Shulchan Aruch rules that one only violates the prohibition of withholding wages if the worker asks for immediate payment. If a worker agrees to delay payment, one no longer violates the prohibition (C.M. 339:8-10). The Zohar, however, writes that it is improper to withhold wages even with the worker’s permission. Some also infer from the language of the Gemara and Shulchan Aruch that although one doesn’t violate if the worker doesn’t ask for pay, it is still proper to pay immediately (Pischei Teshuva 339:7; but see Erech Shai 339:10). When the bill arrives, although “bal talin” no longer applies, there is a rabbinic obligation to pay any due debt as soon as possible, based on the verse, “al tomar l’reiacha” – “Do not tell your neighbor, ‘Leave and come back; I will give tomorrow,’ when it is by you (Mishlei 3:28)”, but this obligation is more flexible, such as if the patient is very busy or low on cash (C.M. 339:7).

Thus, it is preferable to pay immediately, but it is acceptable to wait until the bill arrives. When you receive the bill, you should pay it as soon as feasible.