I've never had anyone check my ID in 10 years. Confident no-one checks any lists from the hotels...if in the hotels even bother sending one.

Terms are usually specified in rate description and I doubt they read those to you if you make a reservation over the phone. I don't think that makes you any more eligible though.
Government rate eligibility for example is enforced much more stringently but it's not any different in concept.

If we take a corporate rate that's not ours it's a misrepresentation and there will always be YMMV there aside from ethical issues.

A FUNNY TAKE ON CORP RATES:

29 yrs ago for my honeymoon I use corp rate to get a really really discounted suite.
But my fellow workers, prankster that they are switch me to a single room with two single beds as a joke and the hotel assisted. After dinner we went back to the hotel not happy campers and was then told we were upgraded to the top floor suite.

And Alan Funt hopped out from behind the wall? ;)

Seriously - this is one reason that I don't tell folks where I'm staying.... or what room. I've worked with enough folks that actually WOULD pull a stunt like this (and several that had no problem making bar & restaurant charges to a room other than their own).

If your law prof gave you that example then you might want to consider switching law schools!

The rental car example is different because insurance is extended. And even in that example the result would be that there is no coverage and the renter would be responsible for the damages. It still would not be fraud. Obtaining insurance coverage by fraudulent means is insurance fraud. But the coverage would be extended to employees of the company. The mere fact that the OP misrepresented himself as an employee would mean there was no coverage and therefore no insurance fraud.

In the situation decribed by the OP he simply claimed a relationship to obtain a lower rate. It might be "theft of service by deception" or something for a minor amount of money (the discount) but it hardly raises to the level of fraud. The hotel might have a cause of action for the discount offered based on the deception but that would be civil rather than criminal. Fraud is criminal.

The hotel example is more like going to a grocery store and claiming to be a member of the store's loyalty club to get a discount. If the store takes your word for it and offers the discount without proof it is their problem.

I used to travel a lot on business related to government contracts. Theoretically I had to give the Federal contract number to get a governmnet rate. In over 20 years I have never once been asked to provide a contract number. I have been asked for government ID on occasion and truthfully answered that I was not a government employee but was entitled to a gov't rate as a gov't contractor. In every case that worked.

Entitled to a gov't rate? Uhmm... Actually....no. Many hotels such as this one in Boston, are enforcing the below:

Rate Plan Description: GOVERNMENT RATE-ID REQUIRED Not valid for Government Contracted vendors. Identification required.

Being a Government contractor doesn't automaticially mean you get Government rate. Make sure you check the T&C first. I was checking in yesterday and the two gentlemen in front of me got that surprise. They wound up paying full rack rate before it was all done.

It depends. Some government contracts specify use of hotels that meet the official per diem rate and extend the government rate to work done under the contract. Most do (or did, it's been 5 years since I traveled that way) and I suspect that if the issue were pursued the hotel would be refunding the difference to those gentlemen. Basically on cost-plus contracts the government would have to pay the higher rate eventually.

I travel now and stay in hotels that have a contracted rate with my state government. They routinely give me a higher rate at checkin. I used to argue but now I ignore that because when they are paid they are only paid the contracted rate regardless of what was done at checkin. They bill for higher and are simply paid the agreed rate.