I don't think that I've ever posted related to the Americans with Disabilities Act (ADA) and how it effects point of sale systems. Mostly it seems that POS systems are designed to accommodate employees with various capabilities. Recently, I've run in to a couple of retailers who had been advised that that the payment terminals for the POS system needed to be lowered (or the whole counter needed to be lowered).
Obviously you never want to make it difficult for anyone to make a purchase in your business so it is wise to be familiar with any guidelines related to counter height and general accessibility. It is possible that fines could be levied should your store not be in compliance.
As I am in no way an expert in this subject matter - it would be great if anyone who has some expertise could chime in. All I've seen in my travels is either one check out stand with a lowered counter or some payment terminals mounted on arms that can be rotated out and down to a suitable height.
If you are willing to contribute, please contact me at firstname.lastname@example.org or 208-340-5632. Thanks!